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19-4217; Rev 0; 11/08
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
General Description
The MAX9791 combines a stereo 2W Class D power amplifier, a stereo 180mW DirectDrive (R) headphone amplifier, and a 120mA low-dropout (LDO) linear regulator in a single device. The MAX9792 combines a mono 3W Class D power amplifier, a stereo 180mW DirectDrive headphone amplifier, and a 120mA LDO linear regulator in a single device. The MAX9791/MAX9792 feature Maxim's patented** DirectDrive headphone amplifier architecture that produces a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. High 107dB DC PSRR and low 0.006% THD+N ensure clean, low-distortion amplification of the audio signal. The ground sense feature senses and corrects for the voltage difference between the output jack ground and device signal ground. This feature minimizes headphone amplifier crosstalk by sensing the impedance in the ground return trace and correcting for it at the output jack. This feature also minimizes ground-loop noise when the output socket is used as a line out connection to other grounded equipment (for example, a PC connected to a home hi-fi system). The MAX9791/MAX9792 feature low RF susceptibility, allowing the amplifiers to successfully operate in close proximity to wireless applications. The MAX9791/ MAX9792 Class D amplifiers feature Maxim's patented spread-spectrum modulation and patented active emissions limiting circuitry. Industry-leading click-andpop suppression eliminates audible transients during power-up and shutdown cycles. The MAX9791/MAX9792 wake-on-beep feature wakes up the speaker and headphone amplifiers when a qualified beep signal is detected at the BEEP input. For maximum flexibility, separate speaker and headphone amplifier control inputs provide independent shutdown of the speaker and headphone amplifiers. Additionally the LDO can be enabled independently of the audio amplifiers. The MAX9791/MAX9792 feature thermal-overload and output short-circuit protection. The devices are available in 28-pin TQFN packages and are specified over the -40C to +85C extended temperature range.
Features
Windows Vista(R) Premium Compliant Low EMI Filterless Class D Speaker Amplifiers Pass EN55022B Emissions Limit with 30cm of Speaker Cable 180mW DirectDrive Headphone Amplifier Excellent RF Immunity Integrated 120mA LDO Eliminates Headphone Ground Loop Noise Wake-on-Beep Function Click-and-Pop Suppression Short-Circuit and Thermal-Overload Protection Thermally Efficient, Space-Saving Package 28-Pin TQFN-EP (4mm x 4mm x 0.75mm)
MAX9791/MAX9792
Ordering Information
PART MAX9791AETI+ MAX9791BETI+ MAX9792AETI+ STEREO/ MONO Stereo Stereo Mono LDO OUTPUT 4.75V 3.3V 4.75V PIN-PACKAGE 28 TQFN-EP* 28 TQFN-EP* 28 TQFN-EP*
Note: All devices are specified over the -40C to +85C extended temperature range. +Denotes a lead-free/RoHS-compliant package. *EP = Exposed pad.
Simplified Block Diagrams
SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 2.7V TO 5.5V
CLASS D AMP
MAX9791A MAX9791B
CLASS D AMP
Applications
Notebook Computers Tablet PCs Portable Multimedia Players
Windows Vista is a registered trademark of Microsoft Corp.
**U.S. Patent #7,061,327. U.S. Patent #6,847,257. U.S. Patent #7,190,225.
4.5V TO 5.5V SPKR_EN HP_EN LDO_EN BEEP LDO 3.3V OR 4.75V
Simplified Block Diagrams continued at end of data sheet. DirectDrive is a registered trademark of Maxim Integrated Products, Inc.
1
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (AVDD, PVDD, HPVDD to GND)........................-0.3V to +6.0V GND to PGND, CPGND ......................................................0.3V CPVSS, C1N to GND ............................................-6.0V to + 0.3V HPL, HPR to CPVSS ...........................................-0.3V to lower of (HPVDD - CPVSS + 0.3V) and +9V HPL, HPR to HPVDD..................................+0.3V to the higher of (CPVSS - HPVDD - 0.3V) and -9V COM, SENSE........................................................-0.3V to + 0.3V Any Other Pin ..........................................-0.3V to (AVDD + 0.3V) Duration of Short Circuit between OUT_+, OUT_- and GND, PGND, AVDD, or PVDD..........................................Continuous Duration of Short Circuit between LDO_OUT and AVDD, GND (Note 1) .........................................................Continuous Duration of Short Circuit between HPR, HPL and GND .......................................................................Continuous Continuous Current (PVDD, OUT_+, OUT_-, PGND)............1.7A Continuous Current (C1N, C1P, CPVSS, AVDD, HPVDD, LDO_OUT, HPR, HPL) ..................................................850mA Continuous Input Current (All Other Pins) ........................20mA Continuous Power Dissipation (TA = +70C) 28-Pin Thin QFN Single-Layer Board (derate 20.8mW/C above +70C)..........................................................1667mW Junction-to-Ambient Thermal Resistance (JA) (Note 2) .....................................................................40C/W Junction-to-Case Thermal Resistance (JC) (Note 2) ....................................................................2.7C/W 28-Pin Thin QFN Multilayer Board (derate 28.6mW/C above +70C)..........................................................2286mW Junction-to-Ambient Thermal Resistance (JA) (Note 2) .....................................................................35C/W Junction-to-Case Thermal Resistance (JC) (Note 2) ....................................................................2.7C/W ESD Protection, Human Body Model ...................................2kV Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
Note 1: If short is present at power-up. Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 3)
PARAMETER GENERAL Supply Voltage Headphone Supply Voltage Undervoltage Lockout VAVDD, VPVDD VHPVDD UVLO SPKR_EN Quiescent Current IAVDD + IPVDD + IHPVDD ISHDN VBIAS tON 1 1 0 0 Shutdown Current Bias Voltage Shutdown to Full Operation Overtemperature Threshold 1 HP_EN 0 1 0 1 0 LDO_EN 1 0 0 0 0 250 4.4 10.5 14.4 0.1 0 0.4 +150 400 6 15 21 1 A mA mA mA A V ms C Guaranteed by PSRR test Guaranteed by PSRR test 4.5 2.7 5.5 5.5 2.65 V V V SYMBOL CONDITIONS MIN TYP MAX UNITS
HP_INR, HP_INL, SPKR_INR, SPKR_INL
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 3)
PARAMETER SPEAKER AMPLIFIER RL = 4 (MAX9791) RL = 8 (MAX9791) RL = 3 (MAX9792) RL = 4 (MAX9791) RL = 8 (MAX9791) RL = 3 (MAX9792) 1.7 1.2 3 W 2.2 1.5 3.7 0.04 0.03 60 80 73 75 62 20 12 3 -52.4 dBV -54 98 dB 20Hz to 20kHz 94 38 78 70 77 dB VRMS 10 k dB mV dB % THD+N = 10%, f = 1kHz, TA = +25C (Note 4) SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX9791/MAX9792
THD+N = 1%, f = 1kHz, TA = +25C (Note 4) Output Power POUT
Total Harmonic Distortion Plus Noise
THD+N
RL = 8, POUT = 500mW, f = 1kHz (Note 4) RL = 4, POUT = 500mW, f = 1kHz (Note 4) VAVDD = VPVDD = 4.5V to 5.5V, TA = +25C f = 217Hz, 200mVP-P f = 1kHz, 200mVP-P f = 10kHz, 200mVP-P Guaranteed by design RIN1 = 20k Measured between OUT_+ and OUT_-, TA = +25C RL = 8, peak voltage, A-weighted, 32 samples per second (Notes 4, 5, and 6) RL = 8 POUT = 1.2W fIN = 1kHz, (Note 4) A-weighted L to R, R to L, RL = 8, VIN = -20dBFS = 100mVRMS, fIN = 1kHz (Note 4) Into shutdown Out of shutdown A-weighted
Power-Supply Rejection Ratio
PSRR
Feedback Impedance Gain Output Offset Voltage
RFSKR AV VOS
Click-and-Pop Level
KCP
Signal-to-Noise Ratio Noise
SNR VN
Crosstalk
L to R, R to L, RL = 8, VIN = -20dBFS = 100mVRMS, fIN = 15kHz (Note 4) HP to SPKR, RLSPKR = 8, PHP = 20mW, RLHP = 32, fIN = 1kHz (Note 4)
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 3)
PARAMETER Class D Switching Frequency Spread-Spectrum Bandwidth Efficiency HEADPHONE AMPLIFIER Output Power POUT THD+N = 1%, f = 1kHz, TA = +25C RL = 16 RL = 32 100 mW 180 -78 dBFS -87 0.006 0.014 70 107 91 80 38.2 RIN2 = 40.2k TA = +25C RL = 32, peak voltage, A-weighted, 32 samples per second (Notes 5, 6) RL = 32, POUT = 40mW, fIN = 1kHz A-weighted No sustained oscillations L to R, R to L, fIN = 1kHz, COM and SENSE connected Crosstalk L to R, R to L, fIN = 15kHz, COM and SENSE connected RL = 32, VIN = -20dBFS = 30mVRMS RL = 10k, VIN = -20dBFS = 0.7mVRMS RL = 32, VIN = -20dBFS = 30mVRMS RL = 10k, VIN = -20dBFS = 70.7mVRMS Into shutdown Out of shutdown A-weighted 20Hz to 20kHz 40.2 0 0.3 -81 dBV -72.5 102 94 8 100 82 89 64 70 80 dB dB VRMS pF 3 42.2 k dB mV dB % POUT = 1.5W, fIN = 1kHz, RL = 8 (Note 4) SYMBOL fSPK CONDITIONS MIN 948 15 83 TYP MAX 1158 UNITS kHz kHz %
RL = 32, fIN = 6kHz, 20kHz AES17, VIN = -3dBFS = 212mVRMS Total Harmonic Distortion Plus Noise THD+N RL = 10k, fIN = 6kHz, 20kHz AES17, VIN = -3dBFS = 500mVRMS RL = 32, POUT = 100mW, f = 1kHz RL = 16, POUT = 75mW, f = 1kHz VHPVDD = 2.7V to 5.5V, TA = +25C Power-Supply Rejection Ratio Feedback Impedance Gain Output Offset Voltage Click-and-Pop Level PSRR RFHP AV VOS KCP f = 1kHz, VRIPPLE = 200mVP-P f = 10kHz, VRIPPLE = 200mVP-P
Signal-to-Noise Ratio Noise Maximum Capacitive Load Drive
SNR VN CL
SPKR to HP, RLSPKR = 8, PSPKR = 1W, RLHP = 32, fIN = 1Hz
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 3)
PARAMETER COM Input Range Common-Mode Rejection Ratio Slew Rate Charge-Pump Frequency BEEP INPUT (LDO_EN = 1) Beep Signal Minimum Frequency Amplifier Turn-On Time Amplifier Hold Time fBEEP tONBEEP tHOLDBEEP Inferred from line regulation, VLDO_OUT = 4.75V Inferred from load regulation 300 Speaker to LDO, VLDO_OUT = 4.75V, f =1kHz, ILDO_OUT = 10mA, speaker POUT = 1.2W, RL = 8 VLDO_OUT = 4.75V VLDO_OUT = 3.3V VDO VLDO_OUT = 4.75V, TA = +25C (Note 7) VAVDD = 4.5V to 5.5V, ILDO_OUT = 1mA IOUT = 50mA IOUT = 120mA 46 106 30 VLDO_OUT = 4.75V VLDO_OUT = 3.3V -4.8 -4 1.5 0.2 0.22 56 dB f = 10kHz 40 130 VRMS +4.8 mV/V +4 mV/mA -80 1.5 1.5 221 Four-cycle count 215 400 246 271 Hz s ms SYMBOL VCOM CMRR SR fOSC CONDITIONS Inferred from CMRR test -300mV < VCOM < +300mV MIN -300 60 0.38 530 TYP MAX +300 UNITS mV dB V/s kHz
MAX9791/MAX9792
LOW-DROPOUT LINEAR REGULATOR Regulator Input Voltage Range LDO Ground Current Output Current Current Limit Crosstalk VAVDD ILDO IOUT ILIM 4.5 0.25 5.5 0.4 120 V mA mA mA dB
Output-Voltage Accuracy Dropout Voltage Startup Time Line Regulation
% mV s
Load Regulation
VLDO_OUT = 4.75V, 1mA < ILDO_OUT < 120mA VRIPPLE = 200mVP-P, VLDO_OUT = 4.75V ILDO_OUT = 10mA f = 1kHz
Ripple Rejection
Output-Voltage Noise
20Hz to 20kHz, CLDO_OUT = 2 x 1F, ILDO_OUT = 120mA VINH VINL -1 2
DIGITAL INPUTS (SPKR_EN, HP_EN, LDO_EN, BEEP) Input-Voltage High Input-Voltage Low Input Bias Current V 0.4 +1 V A
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 3) Note 3: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design. Note 4: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For RL = 3, L = 22H. For RL = 4, L = 33H. For RL = 8, L = 68H. Note 5: Specified at TA = +25C with an 8 + 68H load connected across BTL output for speaker amplifier. Specified at TA = +25C with a 32 resistive load connected between HPR, HPL and GND for headphone amplifier. Speaker and headphone mode transitions are controlled by SPKR_EN and HP_EN inputs, respectively. Note 6: Amplifier Inputs AC-coupled to GND. Note 7: Guaranteed by ATE characterization; limits are not production tested.
Typical Operating Characteristics
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
SPEAKER
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (MAX9792 SPEAKER MODE)
MAX9791 toc01
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (MAX9791 SPEAKER MODE)
MAX9791 toc02
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (MAX9791 SPEAKER MODE)
-10 -20 -30 THD+N (dBFS) RL = 8 VIN = -3dBFS
MAX9791 toc03
0 -10 -20 -30 THD+N (dBFS) RL = 3 VIN = -3dBFS
0 -10 -20 -30 THD+N (dBFS) -40 -50 -60 -70 -80 FS = 707mVRMS RL = 4 VIN = -3dBFS
0
-40 -50 -60 -70 -80 -90 -100 0.01 0.1 1 FREQUENCY (kHz) 10 100 FS = 707mVRMS FS = 1VRMS
-40 -50 -60 -70
FS = 707mVRMS
FS = 1VRMS
-80 -90 -100
FS = 1VRMS
-90 -100 0.01 0.1 1 FREQUENCY (kHz) 10 100
0.01
0.1
1 FREQUENCY (kHz)
10
100
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (MAX9792 SPEAKER MODE)
MAX9791 toc04
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (MAX9791 SPEAKER MODE)
MAX9791 toc05
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (MAX9791 SPEAKER MODE)
RL = 8 10 f = 6kHz THD+N (%) 1 f = 1kHz
MAX9791 toc06
100 RL = 3 10 f = 6kHz THD+N (%)
100 RL = 4 10 f = 6kHz THD+N (%) 1 f = 1kHz
100
1 f = 1kHz 0.1
0.1
0.1
0.01
f = 100Hz
0.01
f = 100Hz
0.01 f = 100Hz 0.001
0.001 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 OUTPUT POWER (W)
0.001 0 0.5 1.0 1.5 2.0 2.5 3.0 OUTPUT POWER (W)
0
0.5
1.0 OUTPUT POWER (W)
1.5
2.0
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
MAX9791/MAX9792
SPEAKER
OUTPUT POWER vs. LOAD RESISTANCE (MAX9792 SPEAKER MODE)
MAX9791 toc07
OUTPUT POWER vs. LOAD RESISTANCE (MAX9791 SPEAKER MODE)
f = 1kHz THD+N = 10%
MAX9791 toc08
EFFICIENCY vs. OUTPUT POWER (MAX9792 SPEAKER MODE)
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 RL = 8
MAX9791 toc09
5.0 4.5 4.0 OUTPUT POWER (W) 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 1 10
f = 1kHz THD+N = 10%
3.0 2.5 OUTPUT POWER (W) 2.0
110
THD+N = 1% 1.5 1.0 0.5 0
RL = 3
THD+N = 1%
fIN = 1kHz
100
1
10 LOAD RESISTANCE ()
100
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
LOAD RESISTANCE ()
OUTPUT POWER (W)
EFFICIENCY vs. OUTPUT POWER (MAX9791 SPEAKER MODE)
MAX9791 toc10
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (SPEAKER MODE)
MAX9791 toc11
CROSSTALK vs. FREQUENCY (SPEAKER MODE)
-10 -20 -30 CROSSTALK (dB) -40 -50 -60 -70 -80 -90 -100 -110 LEFT TO RIGHT 0.01 0.1 1 FREQUENCY (kHz) 10 100 RIGHT TO LEFT FS = 1VRMS VIN = -20dBFS RL = 8
MAX9791 toc12
100 90 80 EFFICIENCY (%) 70 RL = 4 RL = 8
0 -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 RIGHT LEFT VRIPPLE = 200mVP-P RL = 8
0
60 50 40 30 20 10 0 0 0.3 0.6 0.9
fIN = 1kHz
-90 -100 1.8 0.01 0.1 1 FREQUENCY (kHz) 10 100
1.2
1.5
OUTPUT POWER (W)
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
SPEAKER
SPEAKER STARTUP WAVEFORM
MAX9791 toc13
SPEAKER SHUTDOWN WAVEFORM
MAX9791 toc14
SPKR_EN 2V/div
SPKR_EN 2V/div
SPEAKER OUT
SPEAKER OUT
200s/div
200s/div
WIDEBAND OUTPUT SPECTRUM (SPEAKER MODE)
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 0
MAX9791 toc15
OUTPUT FREQUENCY SPECTRUM (SPEAKER MODE)
VOUT = -60dBV f = 1kHz RL = 8 UNWEIGHTED
MAX9791 toc16
0 -20 OUTPUT MAGNITUDE (dBV) -40 -60 -80 -100 -120 -140
OUTPUT AMPLITUDE (dBV)
RBW = 1kHz INPUT AC GROUNDED 1 10 100
1
5
10 FREQUENCY (kHz)
15
20
FREQUENCY (MHz)
8
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
MAX9791/MAX9792
HEADPHONE
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc17
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc18
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
RL = 32 VIN = -3dBFS -60 THD+N (dBFS)
MAX9791 toc19
-50 RL = 16 VIN = -3dBFS -60 THD+N (dBFS)
-50 VHPVDD = 3V RL = 16 VIN = -3dBFS FS = 300mVRMS
-50
-60 THD+N (dBFS)
-70
FS = 300mVRMS
-70
-70 FS = 300mVRMS -80
-80 FS = 1VRMS -90
-80 FS = 1VRMS -90
-90 FS = 1VRMS
-100 0.01 0.1 1 FREQUENCY (kHz) 10 100
-100 0.01 0.1 1 FREQUENCY (kHz) 10 100
-100 0.01 0.1 1 FREQUENCY (kHz) 10 100
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc20
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9791 toc21
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
RL = 32 10 THD+N (%)
MAX9791 toc22
-50 VHPVDD = 3V RL = 32 VIN = -3dBFS
100 RL = 16 10 THD+N (%)
100
-60 THD+N (dBFS)
-70 FS = 300mVRMS -80
1 f = 6kHz 0.1 f = 1kHz
1 f = 1kHz f = 100Hz f = 6kHz
0.1
-90 FS = 1VRMS -100 0.01 0.1 1 FREQUENCY (kHz) 10 100
0.01 f = 100Hz 0.001 0 40 80 120 160 200 OUTPUT POWER (mW)
0.01
0.001 0 50 100 150 200 250 OUTPUT POWER (mW)
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9791 toc23
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9791 toc24A
OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE)
f = 1kHz THD+N = 10%
MAX9791 toc25
100 VHPVDD = 3V RL = 16 10 THD+N (%)
100 VHPVDD = 3V RL = 32 10 THD+N (%)
250
200 OUTPUT POWER (mW)
1 f = 100Hz 0.1 f = 1kHz 0.01 f = 6kHz
1
150
THD+N = 1%
0.1 f = 100Hz 0.01
f = 1kHz
100
50 f = 6kHz
0.001 0 10 20 30 40 50 60 70 80 90 OUTPUT POWER (mW)
0.001 0 10 20 30 40 50 60 70 OUTPUT POWER (mW)
0 1 10 LOAD RESISTANCE () 100
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9
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
HEADPHONE
OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE)
MAX9791 toc26
POWER DISSIPATION vs. OUTPUT POWER (HEADPHONE MODE)
MAX9791 toc27
POWER DISSIPATION vs. OUTPUT POWER (HEADPHONE MODE)
POWER DISSIPATION PER CHANNEL (mW) VHPVDD = 3V 250 200 150 100 50 0 RL = 16
MAX9791 toc28
90 80 70 OUTPUT POWER (mW) 60 50 40 30 20 10 0 10 100
POWER DISSIPATION PER CHANNEL (mW)
VHPVDD = 3V f = 1kHz THD+N = 10%
400 350 300 250 200 150 100 50 0 0 25 50 75 RL = 32 RL = 16
300
THD+N = 1%
RL = 32
1000
100 125 150 175 200
0
20
40
60
80
100
LOAD RESISTANCE ()
PER CHANNEL OUTPUT POWER (mW)
PER CHANNEL OUTPUT POWER (mW)
HEADPHONE OUTPUT POWER vs. HPVDD VOLTAGE
MAX9791 toc29
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc30
CROSSTALK vs. FREQUENCY (HEADPHONE MODE)
-30 -40 CROSSTALK (dB) -50 -60 -70 -80 RIGHT TO LEFT COM AND SENSE RL = 32 RIGHT TO LEFT FS = 300mVRMS COM AND SENSE VIN = -20dBFS DISABLED RIGHT TO LEFT COM AND SENSE DISABLED
MAX9791 toc31
250 HEADPHONE OUTPUT POWER (mW) THD+N = 1% f = 1kHz 200 RL = 32
0 -10 -20 -30 -40 PSRR (dB) -50 -60 -70 -80 -90 -100 -110 -120 LEFT 0.01 0.1 1 FREQUENCY (kHz) 10 RIGHT VRIPPLE = 200mVP-P RL = 32
-20
150
100 RL = 16
50
-90 -100 100 0.01 0.1 1
LEFT TO RIGHT COM AND SENSE 10 100
0 3.0 3.5 4.0 4.5 5.0 5.5 VHPVDD (V)
FREQUENCY (kHz)
OUTPUT FREQUENCY SPECTRUM (HEADPHONE MODE)
OUTPUT FREQUENCY SPECTRUM (dB) 0 -20 -40 -60 -80 -100 -120 -140 0 5 10 FREQUENCY (kHz) 15 20 RIGHT AND LEFT FS = 707mVRMS VIN = -60dBFS RL = 32
MAX9791 toc32
STARTUP WAVEFORM
MAX9791 toc33
HP_EN 2V/div
HP_ 500mV/div
200s/div
10
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
MAX9791/MAX9792
HEADPHONE
SHUTDOWN WAVEFORM
MAX9791 toc34
HEADPHONE RF IMMUNITY vs. FREQUENCY
-10 -30 HP_EN 2V/div AMPLITUDE (dBV) -50 LEFT -70 -90 -110 -130 500 1000 1500 2000 2500 3000 FREQUENCY (MHz) RIGHT RL = 32
MAX9791 toc35
HP_ 500mV/div
200s/div
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11
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
LINE OUT
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc36
TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9791 toc37
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
RL = 10k 10 1 THD+N (%) 0.1 0.01 0.001 f = 1kHz 0.0001 f = 6kHz
MAX9791 toc38
0 -10 -20 -30 THD+N (dBFS) -40 -50 -60 -70 -80 -90 -100 -110 0.01 0.1 1 FREQUENCY (kHz) 10 FS = 707mVRMS FS = 1VRMS RL = 10k VIN = -3dBFS
0 -10 -20 -30 THD+N (dBFS) -40 -50 -60 -70 -80 -90 -100 -110 FS = 707mVRMS FS = 1VRMS VHPVDD = 3V RL = 10k VIN = -3dBFS
100
f = 100Hz
100
0.01
0.1
1 FREQUENCY (kHz)
10
100
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
OUTPUT POWER (mW)
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9791 toc39
CROSSTALK vs. FREQUENCY (HEADPHONE MODE)
OUTPUT FREQUENCY SPECTRUM (dB) -30 -40 CROSSTALK (dB) -50 -60 -70 -80 -90 -100 LEFT TO RIGHT COM AND SENSE 0.01 0.1 1 FREQUENCY (kHz) 10 100 RIGHT TO LEFT COM AND SENSE RL = 10k FS = 707mVRMS VIN = -20dBFS
MAX9791 toc40
OUTPUT FREQUENCY SPECTRUM (HEADPHONE MODE)
0 -20 -40 -60 -80 -100 -120 -140 0 5 10 FREQUENCY (kHz) 15 20 RIGHT AND LEFT RL = 10k FS = 300mVRMS VIN = -60dBFS
MAX9791 toc41
100 10 1 THD+N (%) 0.1 0.01 0.001 f = 1kHz 0.0001 0 0.5 1.0 1.5 2.0 2.5 VHPVDD = 3V RL = 10k
-20
f = 6kHz
f = 100Hz
-110 -120 3.0
OUTPUT POWER (mW)
12
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
MAX9791/MAX9792
GENERAL
SUPPLY CURRENT vs. SUPPLY VOLTAGE
LDO_EN = 1 15 SUPPLY CURRENT (mA)
MAX9791 toc42
SHUTDOWN CURRENT vs. SUPPLY VOLTAGE
SPKR_EN = 1 HP_EN = 0 LDO_EN = 0
MAX9791 toc43
20
0.20
10 SPKR_EN = 0 HP_EN = 1 5 SPKR_EN = 0 HP_EN = 0
SHUTDOWN CURRENT (A)
0.16
0.12
0.08
0 SPKR_EN = 1 HP_EN = 0 -5 4.50 4.75 5.00 5.25 5.50 SUPPLY VOLTAGE (V) SPKR_EN = 1 HP_EN = 1
0.04
0 4.50 4.75 5.00 5.25 5.50 SUPPLY VOLTAGE (V)
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13
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
LDO
LDO OUTPUT ACCURACY vs. LOAD CURRENT
MAX9791 toc44
LDO OUTPUT ACCURACY vs. AMPLIFIER OUTPUT POWER
0.09 LDO OUTPUT ACCURACY (%) 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 -1.0 0 300 600 900 1200 1500 -40
MAX9791 toc45
LDO OUTPUT ACCURACY vs. TEMPERATURE
MAX9791 toc46
2.0 1.5 LDO OUTPUT ACCURACY (%) 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 0 25 50 75 100 125
0.10
1.0
LDO OUTPUT ACCURACY (%)
0.5 LDO_OUT = 3.3V
0 LDO_OUT = 4.75V -0.5
150
-15
10
35
60
85
LOAD CURRENT (mA)
AMPLIFIER OUTPUT POWER (mW)
TEMPERATURE (C)
LDO DROPOUT VOLTAGE vs. LOAD
MAX9791 toc47
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY LDO
MAX9791 toc48
LDO OUTPUT NOISE
CLOAD = 2 x 1F ILOAD = 120mA
MAX9791 toc49
300 LDO_OUT = 4.75V LDO DROPOUT VOLTAGE (mV) 250 200
40 20 0 PSRR (dB) -20 -40 -60 -80 -100 LDO_OUT = 3.3V LDO_OUT = 4.74V VRIPPLE = 200mVP-P ILOAD = 10mA
200 175 LDO OUTPUT NOISE (V) 150 125 100 75 50
150 100 50 0 0 50 100 150 ILOAD (mA) 200 250 300
0.01
0.1
1 FREQUENCY (kHz)
10
100
0.01
0.1
1 FREQUENCY (kHz)
10
100
14
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VAVDD = VPVDD = VHPVDD = 5V, VGND = VPGND = VCPGND = 0, ILDO_OUT = 0, CLDO = 2 x 1F, C1 = C2 = 1F. RL = , unless otherwise specified. RIN1 = 20k (AVSPKR = 12dB), RIN2 = 40.2k (AVHP = 0dB), CIN1 = 470nF, CIN2 = CCOM = 1F, measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Speaker mode: SPKR_EN = 0, HP_EN = 0. Headphone mode: SPKR_EN = 1, HP_EN = 1.)
MAX9791/MAX9792
LDO
LINE-TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE
MAX9791 toc50
MAX9791 toc51
CH1 LOW 4.560V
ILDO_OUT 50mV/div
CH1 HIGH 5.500V CH2 LOW 800.0V CH2 HIGH 1.000mV 1.00ms/div 100ms/div AC-COUPLED VLDO_OUT 10mV/div
SHUTDOWN RESPONSE
CROSSTALK vs. FREQUENCY SPEAKER TO LDO
MAX9791 toc52
LDO_EN 2V/div
VLDO_EN 2V/div 200s/div
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130
BOTH SPEAKERS WITH SIGNAL PSPKR = 1.2W RLSPKR = 8W ILDO = 10mA LEFT CHANNEL TO LDO
CROSSTALK (dB)
RIGHT CHANNEL TO LDO
0.01
0.1
1 FREQUENCY (kHz)
10
100
______________________________________________________________________________________
MAX9791 toc53
15
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
MAX9791 Pin Description
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17, 26 18 19 20, 23 21 22 24 25 27 28 -- NAME SPKR_INL HP_INR HP_INL COM GND LDO_OUT AVDD LDO_EN HPR HPL SENSE CPVSS C1N CPGND C1P HPVDD PVDD OUTLOUTL+ PGND BEEP HP_EN OUTR+ OUTRSPKR_EN SPKR_INR EP Left-Channel Speaker Amplifier Input Right-Channel Headphone Amplifier Input Left-Channel Headphone Amplifier Input Common-Mode Voltage Sense Input Signal Ground. Star connect to PGND. LDO Output. Bypass with two 1F ceramic low ESR capacitors to GND. Positive Power-Supply and LDO Input. Bypass with a 0.1F and two 1F capacitors to GND. LDO Enable. Connect LDO_EN to AVDD to enable the LDO. Right-Channel Headphone Amplifier Output Left-Channel Headphone Amplifier Output Headphone Ground Sense Headphone Amplifier Negative Power Supply. Connect a 1F capacitor between CPVSS and PGND. Charge-Pump Flying Capacitor Negative Terminal. Connect a 1F capacitor between C1P and C1N. Charge-Pump Ground. Connect directly to PGND plane. Charge-Pump Flying Capacitor Positive Terminal. Connect a 1F capacitor between C1P and C1N. Headphone Amplifier Positive Power Supply. Connect a 10F capacitor between HPVDD and PGND. Speaker Amplifier Power-Supply Input. Bypass with a 0.1F capacitor to PGND. Left-Channel Speaker Amplifier Output, Negative Phase Left-Channel Speaker Amplifier Output, Positive Phase Power Ground. Star connect to GND. PC Beep Input. Connect to GND if beep detection function is disabled. Active-High Headphone Amplifier Enable Right-Channel Speaker Amplifier Output, Positive Phase Right-Channel Speaker Amplifier Output, Negative Phase Active-Low Speaker Amplifier Enable Right-Channel Speaker Amplifier Input Exposed Pad. Connect to GND. FUNCTION
16
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
MAX9792 Pin Description
PIN 1, 5 2 3 4 6 7 8 9 10 11 12 13 14 15 16 17, 26 18, 25 19, 24 20, 23 21 22 27 28 -- NAME GND HP_INR HP_INL COM LDO_OUT AVDD LDO_EN HPR HPL SENSE CPVSS C1N CPGND C1P HPVDD PVDD OUTOUT+ PGND BEEP HP_EN SPKR_EN SPKR_IN EP Signal Ground. Star connect to PGND. Right-Channel Headphone Amplifier Input Left-Channel Headphone Amplifier Input Common-Mode Voltage Sense Input LDO Output. Bypass with two 1F ceramic low ESR capacitors to GND. Positive Power Supply and LDO Input. Bypass with a 0.1F and two 1F capacitors to GND. LDO Enable. Connect LDO_EN to AVDD to enable the LDO. Right-Channel Headphone Amplifier Output Left-Channel Headphone Amplifier Output Headphone Ground Sense Headphone Amplifier Negative Power Supply. Connect a 1F capacitor between CPVSS and PGND. Charge-Pump Flying Capacitor Negative Terminal. Connect a 1F capacitor between C1P and C1N. Charge-Pump Ground. Connect directly to PGND plane. Charge-Pump Flying Capacitor Positive Terminal. Connect a 1F capacitor between C1P and C1N. Headphone Amplifier Positive Power Supply. Connect a 10F capacitor between HPVDD and PGND. Speaker Amplifier Power-Supply Input. Bypass with a 0.1F capacitor to PGND. Speaker Amplifier Output, Negative Phase Speaker Amplifier Output, Positive Phase Power Ground. Star connect to GND. PC Beep Input. Connect to GND if beep detection function is disabled. Active-High Headphone Amplifier Enable Active-Low Speaker Amplifier Enable Speaker Amplifier Input Exposed Pad. Connect to GND. FUNCTION
MAX9791/MAX9792
Detailed Description
The MAX9791 combines a stereo 2W Class D power amplifier, a stereo 175mW DirectDrive headphone amplifier, and a 120mA LDO linear regulator in a single device. The MAX9792 combines a mono 3W Class D power amplifier, a stereo 175mW DirectDrive headphone amplifier, and a 120mA LDO linear regulator in a single device. The MAX9791/MAX9792 feature wake-on-beep detection, comprehensive click-and-pop suppression, lowpower shutdown mode, and excellent RF immunity. These devices incorporate an integrated LDO that serves as a clean power supply for CODEC or other circuits. The MAX9791/MAX9792 are Windows Vista Premium compliant. See Table 1 for a comparison of the Windows Vista Premium specifications and MAX9791/ MAX9792 specifications.
The MAX9791/MAX9792 feature spread-spectrum modulation and active emission limiting circuitry that offers significant improvements to switch-mode amplifier technology. These devices offer Class AB performance with Class D efficiency in a minimal board-space solution. The headphone amplifiers use Maxim's patented DirectDrive architecture to eliminate the bulky output DC-blocking capacitors required by traditional headphone amplifiers. A charge pump inverts the positive supply (HPVDD) to create a negative supply (CPVSS). The headphone amplifiers operate from these bipolar supplies with their outputs biased about GND. The benefit of the GND bias is that the amplifier outputs no longer have a DC component (typically VDD/2). This feature eliminates the large DC-blocking capacitors required with conventional headphone amplifiers to
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17
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Table 1. Windows Premium Mobile Vista Specifications vs. MAX9791/MAX9792 Specifications
DEVICE TYPE REQUIREMENT THD+N Analog Line-Out Jack (RL = 10k, FS = 0.707VRMS) Dynamic range with signal present Line output crosstalk THD+N Analog Headphone-Out Jack (RL = 32, FS = 0.300VRMS) Dynamic range with signal present Headphone output crosstalk WINDOWS PREMIUM MOBILE VISTA SPECIFICATIONS -65dB FS [100Hz, 20kHz] -80dBV, A-weighted [20Hz, 20kHz] -50dB [20Hz, 15kHz] -45dB FS [100Hz, 20kHz] -60dBV, A-weighted [20Hz, 20kHz] -50dB [20Hz, 15kHz] MAX9791/MAX9792 TYPICAL PERFORMANCE 87dBFS [100Hz, 20kHz] -98.9dB A-weighted [20Hz, 20kHz] 64dB [20Hz, 15kHz] 82dBFS [100Hz, 20kHz] -91.5dB A-weighted [20Hz, 20kHz] 64dB [20Hz, 15kHz]
Note: THD+N, dynamic range with signal present, and crosstalk should be measured in accordance with AES17 audio measurements standards.
EFFICIENCY (%)
conserve board space and system cost, as well as improve low-frequency response and distortion. The MAX9791/MAX9792 amplifiers feature an undervoltage lockout that prevents operation from an insufficient power supply and click-and-pop suppression that eliminates audible transients on startup and shutdown. The amplifiers include thermal overload and short-circuit protection.
EFFICIENCY vs. IDEAL CLASS AB EFFICIENCY
90 80 70 60 50 40 30 20 10 0 0 0.25 0.50 0.75 1.00 1.25 1.50 OUTPUT POWER (W) IDEAL CLASS AB MAX9791
Class D Speaker Amplifier
The MAX9791/MAX9792 integrate a filterless class D amplifier that offers much higher efficiency than class AB amplifiers. The high efficiency of a Class D amplifier is due to the switching operation of the output stage transistors. In a Class D amplifier, the output transistors act as current steering switches and consume negligible additional power. Any power loss associated with the Class D output stage is mostly due to the I2R loss of the MOSFET on-resistance and quiescent current overhead. The theoretical best efficiency of a linear amplifier is 78%, however, that efficiency is only exhibited at peak output power. Under normal operating levels (typical music reproduction levels), efficiency falls below 45%, whereas the MAX9791/MAX9792 exhibit 67% efficiency under the same conditions (Figure 1).
Figure 1. MAX9791 Efficiency vs. Class AB Efficiency
Ultra-Low EMI Filterless Output Stage In traditional Class D amplifiers, the high dv/dt of the rising and falling edge transitions resulted in increased electromagnetic-interference (EMI) emissions, which required the use of external LC filters or shielding to meet EN55022B EMI regulation standards. Limiting the dv/dt normally results in decreased efficiency. Maxim's active emissions limiting circuitry actively limits the dv/dt of the rising and falling edge transitions, providing reduced EMI emissions while maintaining up to 83% efficiency.
18
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
CLASS D EMI PLOT
40 35
VOUT VDD/2 VDD
AMPLITUDE (dBV/m)
30 25 20 15 10 5 30 100 FREQUENCY (MHz)
VOUT GND GND CONVENTIONAL AMPLIFIER BIASING SCHEME +VDD
1000
Figure 2. EMI with 30cm of Speaker Cable
In addition to active emission limiting, the MAX9791/ MAX9792 feature patented spread-spectrum modulation that flattens the wideband spectral components. Proprietary techniques ensure that the cycle-to-cycle variation of the switching period does not degrade audio reproduction or efficiency (see the Typical Operating Characteristics). In spread-spectrum modulation mode, the switching frequency varies randomly by 15kHz around the center frequency (530kHz). The effect is to reduce the peak energy at harmonics of the switching frequency. Above 10MHz, the wideband spectrum looks like noise for EMI purposes (see Figure 2).
-VDD DirectDrive AMPLIFIER BIASING SCHEME
Figure 3. Traditional Amplifier Output vs. MAX9791/MAX9792 DirectDrive Output
Speaker Current Limit When the output current of the speaker amplifier exceeds the current limit (2A, typ) the MAX9791/ MAX9792 disable the outputs for approximately 100s. At the end of 100s, the outputs are re-enabled. If the fault condition still exists, the MAX9791/MAX9792 continue to disable and re-enable the outputs until the fault condition is removed.
DirectDrive Headphone Amplifier
Traditional single-supply headphone amplifiers bias the outputs at a nominal DC voltage (typically half the supply). Large coupling capacitors are needed to block this DC bias from the headphone. Without these capacitors, a significant amount of DC current flows to the headphone, resulting in unnecessary power dissipation and possible damage to both headphone and headphone amplifier.
Maxim's patented DirectDrive architecture uses a charge pump to create an internal negative supply voltage. This allows the headphone outputs of the MAX9791/MAX9792 to be biased at GND while operating from a single supply (Figure 3). Without a DC component, there is no need for the large DC-blocking capacitors. Instead of two large (220F, typ) capacitors, the MAX9791/MAX9792 charge pump requires two small 1F ceramic capacitors, conserving board space, reducing cost, and improving the frequency response of the headphone amplifier. The MAX9791/MAX9792 feature a low-noise charge pump. The nominal switching frequency of 530kHz is well beyond the audio range, and thus does not interfere with audio signals. The switch drivers feature a controlled switching speed that minimizes noise generated by turn-on and turn-off transients. By limiting the switching speed of the charge pump, the di/dt noise caused by the parasitic trace inductance is minimized.
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19
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
RFHP
CROSSTALK vs. GROUND RESISTANCE (RG)
-40 -45
HPL
CIN2 HP_INL RIN2
RS = 5 RL = 32
-50
HPR
CROSSTALK (dB)
CCOM RCOM
-55 -60 -65 -70
COM
RFHP
SENSE
CIN2 RIN2
HP_INR
-75 -80 0
RFHP
0.025
0.050
0.075 RG ()
0.100
0.125
0.150
Figure 4. Connecting COM for Ground Sense
Figure 5. Crosstalk vs. Ground Resistance
Common-Mode Sense Windows Vista-compliant platforms are restricted to only 115m of ground return impedance. If the headphone jack ground is connected close to the audio device ground using a solid ground plane, the return path resistance can be quite low. However, it is often necessary to locate some jacks far from the audio device. The MAX9791/MAX9792 COM and SENSE inputs allow the headphone jack to be placed further away from the device without degrading crosstalk performance.
The MAX9791/MAX9792 SENSE and COM inputs sense and correct for the difference between the headphone return and device ground. When using common-mode sense, connect COM through a resistor to GND of the device (Figure 4). For optimum common-mode rejection, use the same value resistors for RIN2 and RCOM. To improve AC CMRR, add a capacitor equal to CIN2 between GND and RCOM. Configuring SENSE and COM in this way improves system crosstalk performance by reducing the negative effects of the headphone jack ground return resistance. RG Crosstalk in dB = 20 log RL + RS
The headphone amplifier output impedance, trace resistance, and contact resistance of the jack are grouped together to represent the source resistance, RS. The resistance between the load and the sleeve, the sleeve contact resistance, and the system ground return resistance are grouped together to represent the ground resistance, RG. Assuming a typical source resistance of 5, the ground return impedance would need to be limited to 115m to meet Windows Vista's crosstalk specification of 50dB (Figure 5). This is further complicated by the fact that the impedance of the sleeve connection in the 3.5mm stereo jack can make up 30m-90m alone. The MAX9791/MAX9792 COM and SENSE inputs reduce crosstalk performance by eliminating effects of 28.5m of ground return path resistance. If ground sensing is not required, connect COM directly to GND and leave SENSE unconnected (Figure 6).
Wake-on-Beep
The MAX9791/MAX9792 beep-detection circuit wakes up the device (speaker and headphone amplifiers) once a qualified beep signal is detected at BEEP and the LDO is enabled. The amplifier wake command from the beep-detection circuit overrides the logic signal applied at HP_EN and SPKR_EN.
20
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
A qualified BEEP signal consists of a 3.3V typical, 215Hz minimum signal that is present at BEEP for four consecutive cycles. Once the first rising edge transition is detected at BEEP, the beep circuit wakes up and begins counting the beep cycles. Once four consecutive cycles of a qualified beep signal are counted, the device (speaker and headphone amplifiers) enables within 400s. If the first rising edge is not followed by three consecutive rising edges within 16ms, the device remains shutdown (i.e., glitch protection). The device (speaker and headphone amplifiers) returns to its programmed logic state once 246ms has elapsed from the time the last rising edge was detected. This 246ms amplifier hold time ensures complete beep profiles are passed to the amplifier outputs (Figure 7). Ground BEEP when the wake-on-beep feature is not used. Do not leave BEEP unconnected.
MAX9791/MAX9792
CROSSTALK vs. FREQUENCY (HEADPHONE MODE)
-20 -30 -40 CROSSTALK (dB) -50 -60 -70 -80 -90 -100 0.01 0.1 1 FREQUENCY (kHz) 10 100 LEFT TO RIGHT COM AND SENSE RIGHT TO LEFT COM AND SENSE RIGHT TO LEFT COM AND SENSE DISABLED LEFT TO RIGHT COM AND SENSE DISABLED RL = 32 FS = 300mVRMS VOUT = -20dBFS
Low-Dropout Linear Regulator
The LDO regulator can be used to provide a clean power supply to a CODEC or other circuitry. The LDO can be enabled independently of the audio amplifiers. Set LDO_EN = AVDD to enable the LDO or set LDO_EN = GND to disable the LDO. The LDO can provide up to 120mA of continuous current.
Figure 6. MAX9791/MAX9792 COM and SENSE Inputs Reduce Crosstalk
time, connect SPKR_EN and HP_EN together, allowing a single logic voltage to enable either the speaker or the headphone amplifier as shown in Figure 8.
Speaker and Headphone Amplifier Enable
The MAX9791/MAX9792 feature control inputs for the independent enabling of the speaker and headphone amplifiers, allowing both to be active simultaneously if required. Driving SPKR_EN high disables the speaker amplifiers. Driving HP_EN low independently disables the headphone amplifiers. For applications that require only one of the amplifiers to be on at a given
Shutdown
The MAX9791/MAX9792 feature a low-power shutdown mode, drawing 0.1A of supply current. By disabling the speaker, headphone amplifiers, and the LDO, the MAX9791/MAX9792 enter low-power shutdown mode. Set SPKR_EN to AVDD and HP_EN and LDO_EN to GND to disable the speaker amplifiers, headphone amplifiers, and LDO, respectively.
16ms
BEEP
1
2
3
4 240ms
SPKR AND HP AMPS ENABLE 400s
Figure 7. Qualified BEEP Signal Timing
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21
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
MAX9791
MAX9791A/B MAX9792A
SINGLE CONTROL SPKR_EN HP_EN CIN1 RIN1 SPKR_IN_
RFB 20k MONO CLASS D AMPLIFIER OUT_+ OUT_-
Figure 8. Enabling Either the Speaker or Headphone Amplifier with a Single Control Pin
Figure 9. Setting Speaker Amplifier Gain
Click-and-Pop Suppression
The MAX9791/MAX9792 feature a common-mode bias voltage of 0V. A 0V BIAS allows the MAX9791/MAX9792 to quickly turn on/off with no resulting clicks and pops. With the HDA CODEC outputs biased and the MAX9791/MAX9792 inputs sitting as 0V in shutdown and normal operation, the RIN x CIN time constant is eliminated.
Applications Information
Filterless Class D Operation
Traditional Class D amplifiers require an output filter to recover the audio signal from the amplifier's output. The filters add cost and size and can decrease efficiency and THD+N performance. The traditional PWM scheme uses large differential output swings (2 x PVDD peakto-peak) causing large ripple currents. Any parasitic resistance in the filter components results in a loss of power, lowering the efficiency. The MAX9791/MAX9792 do not require an output filter. The devices rely on the inherent inductance of the speaker coil and the natural filtering of both the speaker and the human ear to recover the audio component of the square-wave output. Eliminating the output filter results in a smaller, less costly, and more efficient solution. Because the frequency of the MAX9791/MAX9792 output is well beyond the bandwidth of most speakers, voice coil movement due to the square-wave frequency is very small. For optimum results, use a speaker with a series inductance > 10H. Typical 8 speakers exhibit series inductances in the 20H to 100H range.
Speaker Amplifier The MAX9791/MAX9792 speaker amplifiers feature Maxim's comprehensive, industry leading click-andpop suppression. During startup and shutdown, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device. Headphone Amplifier In conventional single-supply headphone amplifiers, the output-coupling capacitor is a major contributor of audible clicks and pops. Upon startup, the amplifier charges the coupling capacitor to its bias voltage, typically V DD/2. During shutdown, the capacitor is discharged to GND; a DC shift across the capacitor results, which in turn appears as an audible transient at the speaker. Because the MAX9791/MAX9792 do not require output-coupling capacitors, no audible transient occurs. The MAX9791/MAX9792 headphone amplifiers feature extensive click-and-pop suppression that eliminates any audible transient sources internal to the device.
22
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Setting Speaker Amplifier Gain External input resistors in conjunction with the internal feedback resistors (RFSPKR) set the speaker amplifier gain of the MAX9791/MAX9792. Set gain by using resistor RIN1 as follows (Figure 9):
20k A VSPKR = -4 V/V RIN1 where AVSPKR is the desired voltage gain. An RIN1 of 20k yields a gain of 4V/V, or 12dB.
*L1 = L2 = WURTH 742792040
MAX9791/MAX9792
MAX9791A/B MAX9792A
L1*
L2* 330pF 330pF
Component Selection
Optional Ferrite Bead Filter In applications where speaker leads exceed 15cm, use a filter constructed from a ferrite bead and a capacitor to ground (Figure 10) to provide additional EMI suppression. Use a ferrite bead with low DC resistance, high frequency (> 1.2MHz) impedance of 100 to 600, and rated for at least 1A. The capacitor value varies based on the ferrite bead chosen and the actual speaker lead length. Select the capacitor value based on EMI performance.
Figure 10. Optional Ferrite Bead Filter
TOTAL HARMONIC DISTORTION + NOISE vs. OUTPUT POWER (HEADPHONE MODE)
100 RL = 32 10 OUT OF PHASE
THD+N (%)
1
0.1
IN PHASE
Output Power (Headphone Amplifier)
The headphone amplifiers are specified for the worstcase scenario when both inputs are in phase. Under this condition, the drivers simultaneously draw current from the charge pump, leading to a slight loss in headroom of CPVSS. In typical stereo audio applications, the left and right signals have differences in both magnitude and phase, subsequently leading to an increase in the maximum attainable output power. Figure 11 shows the two extreme cases for in and out of phase. In most cases, the available power lies between these extremes.
0.01
0.001 0 50 100 150 200 250 OUTPUT POWER (mW)
Figure 11. Output Power vs. Supply Voltage with Inputs In/Out of Phase; 32W Load Conditions and 3.5dB Gain
Power Supplies
The MAX9791/MAX9792 speaker amplifiers are powered from PVDD with a range from 4.5V to 5.5V. The headphone amplifiers are powered from HPVDD and CPVSS. HPVDD is the positive supply of the headphone amplifiers and charge pump ranging from 2.7V to 5.5V. CPVSS is the negative supply of the headphone amplifiers. The charge pump inverts the voltage at HPVDD, and the resulting voltage appears at CPVSS. AVDD powers the remainder of the device.
Headphone Amplifier Gain
Gain-Setting Resistors External input resistors in conjunction with the internal feedback resistors (RFHP) set the headphone amplifier gain of the MAX9791/MAX9792. Set gain by using resistor RIN2 (Figure 4) as follows:
40.2k A VHP = - V/V RIN2 where AVHP is the desired voltage gain. An RIN2 of 40.2k yields a gain of 1V/V, or 0dB.
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23
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
INPUT COUPLING CAPACITOR-INDUCED THD+N vs. FREQUENCY (HEADPHONE MODE)
-50 0603 10V X7R 10% 1F -60 THD+N (dBFS) VOUT - -3dBFS FS = 1VRMS RL =32 AMPLITUDE (dBV) 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 0 500
SPEAKER RF IMMUNITY vs. FREQUENCY
-70
0603 10V X5R 10% 1F
RIGHT
-80 0805 50V X7R 10% 1F 0402 6.3V X5R 10% 1F -100 10 100 FREQUENCY (kHz) 1000
LEFT
-90
1000
1500
2000
2500
3000
FREQUENCY (MHz)
Figure 12. Input Coupling Capacitor-Induced THD+N vs. Frequency
Figure 13. Speaker RF Immunity
Component Selection
Speaker Amplifier Power-Supply Input (PVDD) PVDD powers the speaker amplifiers. PVDD ranges from 4.5V to 5.5V. Bypass PVDD with a 0.1F capacitor to PGND. Apply additional bulk capacitance at the device if long input traces between PVDD and the power source are used. Headphone Amplifier Power-Supply Input (HPVDD and CPVSS) The headphone amplifiers are powered from HPVDD and CPVSS. HPVDD is the positive supply of the headphone amplifiers and ranges from 2.7V to 5.5V. Bypass HPVDD with a 10F capacitor to PGND. CPVSS is the negative supply of the headphone amplifiers. Bypass CPVSS with a 1F capacitor to PGND. The charge pump inverts the voltage at HPVDD, and the resulting voltage appears at CPVSS. A 1F capacitor should be connected between C1N and C1P. Positive Power Supply and LDO Input (AVDD) The internal LDO and the remainder of the device are powered by AVDD. AVDD ranges from 4.5V to 5.5V. Bypass AVDD with a 0.1F capacitor to GND and two 1F capacitors to GND. Note additional bulk capacitance is required at the device if long input traces between AVDD and the power source are used. Input Filtering The input capacitor (C IN_ ), in conjunction with the amplifier input resistance (RIN_), forms a highpass filter that removes the DC bias from the incoming signal.
24
The AC-coupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero source impedance, the -3dB point of the highpass filter is given by: f -3dB = 1 2RIN _ CIN _
RIN_ is the amplifier's external input resistance value. Choose CIN_ such that f-3dB is well below the lowest frequency of interest. Setting f-3dB too high affects the amplifier's low frequency response. Use capacitors with adequately low-voltage coefficient dielectrics (see Figure 12). Capacitors with higher voltage coefficients, such as ceramics, result in increased distortion at low frequencies.
Charge-Pump Capacitor Selection Use capacitors with an ESR less than 100m for optimum performance. Low ESR ceramic capacitors minimize the output resistance of the charge pump. For best performance over the extended temperature range, select capacitors with an X7R dielectric. Flying Capacitor (C1) The value of the flying capacitor (C1) affects the load regulation and output resistance of the charge pump. A C1 value that is too small degrades the device's ability to provide sufficient current drive, which leads to a loss of output voltage. Connect a 1F capacitor between C1P and C1N.
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Output Capacitor (C2) Connect a 1F capacitor between CPVSS and PGND.
Layout and Grounding
Proper layout and grounding are essential for optimum performance. Use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace resistance, as well as route heat away from the device. Good grounding improves audio performance, minimizes crosstalk between channels, and prevents switching noise from coupling into the audio signal. Connect PGND and GND together at a single point on the PCB. Route PGND and all traces that carry switching transients away from GND, and the traces and components in the audio signal path. Connect C2 to the PGND plane. Place the chargepump capacitors (C1, C2) as close as possible to the device. Bypass PVDD with a 0.1F capacitor to PGND. Place the bypass capacitors as close as possible to the device. The MAX9791/MAX9792 is inherently designed for excellent RF immunity. For best performance, add ground fills around all signal traces on top or bottom PCB planes.
Use large, low-resistance output traces. As load impedance decreases, the current drawn from the device outputs increase. At higher current, the resistance of the output traces decrease the power delivered to the load. For example, if 2W is delivered from the speaker output to a 4 load through a 100m trace, 49mW is wasted in the trace. If power is delivered through a 10m trace, only 5mW is wasted in the trace. Large output, supply, and GND traces also improve the power dissipation of the device. The MAX9791/MAX9792 thin QFN package features an exposed thermal pad on its underside. This pad lowers the package's thermal resistance by providing a direct heat conduction path from the die to the printed circuit board. Connect the exposed thermal pad to GND by using a large pad and multiple vias to the GND plane.
MAX9791/MAX9792
Chip Information
PROCESS: BiCMOS
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Pin Configurations
HPVDD OUTL+ OUTLPGND PGND PVDD OUT+ BEEP PVDD OUTBEEP
C1P
21 HP_EN 22 PGND 23 OUTR+ 24 OUTR- 25 PVDD 26 SPKR_EN 27 SPKR_INR 28 1 SPKR_INL +
20
19
18
17
16
15 14 13 12 CPGND C1N CPVSS SENSE HPL HPR LDO_EN HP_EN 22 PGND 23 OUT+ 24 OUT- 25 PVDD 26 SPKR_EN 27 SPKR_IN 28
21
20
19
18
17
16
15 14 13 12 CPGND C1N CPVSS SENSE HPL HPR LDO_EN
C1P 11 10 9 8 7 AVDD
4.75V
TOP VIEW
TOP VIEW
MAX9791A MAX9791B
*EP
11 10 9 8
MAX9792A
*EP + 1 GND 2 HP_INR 3 HP_INL 4 COM 5 GND 6 LDO_OUT
2 HP_INR
3 HP_INL
4 COM
5 GND
6 LDO_OUT
7 AVDD
TQFN (4mm x 4mm x 0.75mm)
*EP = EXPOSED PAD
TQFN (4mm x 4mm x 0.75mm)
*EP = EXPOSED PAD
Simplified Block Diagrams (continued)
SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 2.7V TO 5.5V
SPKR_IN
CLASS D AMP
MAX9792A
HP_INR
HP_INL SPKR_EN HP_EN LDO_EN BEEP 4.5V TO 5.5V LDO
26
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HPVDD
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
MAX9791A/MAX9791B Block Diagram
4.5V TO 5.5V
MAX9791/MAX9792
0.1F PVDD 17, 26 CIN3 CIN1
RIN3 RIN1
20k SPKR_INL 1 STEREO CLASS D AMPLIFIER
MAX9791A MAX9791B
19 18 OUTL+ OUTL-
CIN1 CIN3 CIN2
RIN1 RIN3
SPKR_INR
28
24 25
OUTR+ OUTR-
20k RIN2 HP_INL 3 40.2k TO HPVDD CIN2 RIN2 10 HP_INR 2 TO CPVSS 4.5V TO 5.5V LDO_EN HP_EN C BEEP INPUT 8 22 CONTROL BEEP 21 SPKR_EN 27 COM 4 40.2k 4.5V TO 5.5V AVDD 1.0F 1.0F 0.1F LDO BLOCK 13 TO CODEC 1.0F 1.0F LDO_OUT 6 5 GND 20, 23 PGND 12 CPVSS C2 1.0F C1N 7 CHARGE PUMP 14 CPGND C1 1.0F TO HPVDD 40.2k 11 16 15 SENSE HPVDD C1P C3 10F 2.7V TO 5.5V 9 HPR HPL
CCOM RCOM
NOTE: LOGIC PINS CONFIGURED FOR: LDO_EN = 1, LDO ENABLED SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED
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27
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
MAX9792A Block Diagram
4.5V TO 5.5V
0.1F PVDD 17, 26
CIN3 CIN1
RIN3 RIN1
MAX9792A MAX9792B
20k SPKR_IN 28 MONO CLASS D AMPLIFIER 40.2k TO HPVDD 19, 24 18, 25 OUT+ OUT-
CIN2
RIN2
HP_INL
3
CIN2
RIN2
10 HP_INR 2 TO CPVSS
HPL
4.5V TO 5.5V
LDO_EN HP_EN
8 22 CONTROL 9 HPR
C BEEP INPUT
BEEP 21 SPKR_EN 27 COM 4 40.2k
TO HPVDD 40.2k 11 16 15 SENSE HPVDD C1P CPGND C1 1.0F C3 10F 2.7V TO 5.5V
CCOM RCOM
4.5V TO 5.5V AVDD 1.0F 1.0F 0.1F LDO BLOCK 7 CHARGE PUMP
14
13 TO CODEC 1.0F 1.0F LDO_OUT 6 1, 5 GND 20, 23 PGND 12 CPVSS C2 1.0F
C1N
NOTE: LOGIC PINS CONFIGURED FOR: LDO_EN = 1, LDO ENABLED SPKR_EN = 0, SPEAKER AMPLIFIER ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED
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Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE 28 TQFN-EP PACKAGE CODE T2844-1 DOCUMENT NO. 21-0139
MAX9791/MAX9792
______________________________________________________________________________________
24L QFN THIN.EPS
29
Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers MAX9791/MAX9792
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
30 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

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