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19-0606; Rev 0; 9/06
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
General Description
The MAX9789A/MAX9790A combine a stereo, 2W Class AB speaker power amplifier with a stereo 100mW DirectDriveTM headphone amplifier in a single device. The MAX9789A/MAX9790A are designed for use with the Microsoft Windows VistaTM operating system and are fully compliant with Microsoft's Windows Vista specifications. The headphone amplifier features Maxim's patented DirectDrive architecture that produces a ground-referenced output from a single supply to eliminate the need for large DC-blocking capacitors, as well as save cost, board space, and component height. A high +90dB PSRR and low 0.002% THD+N ensures clean, low-distortion amplification of the audio signal. Separate speaker and headphone amplifier control inputs provide independent shutdown of the speaker and headphone amplifiers, allowing speaker and headphone amplifiers to be active simultaneously, if required. The industry-leading click-and-pop suppression circuitry reduces audible transients during startup and shutdown cycles. The MAX9789A features an internal LDO that can be used as a clean power supply for a CODEC or other circuits. The LDO output voltage is set internally at 4.75V or can be adjusted between 1.21V and 4.75V using a simple resistive divider. The LDO is protected against thermal overloads and short circuits while providing 120mA of continuous output current and can be enabled independently of the audio amplifiers. By disabling the speaker and headphone amplifiers, and the LDO (for MAX9789A), the MAX9789A/MAX9790A enter low-power shutdown mode and draw only 0.3A. The MAX9789A/MAX9790A operate from a single 4.5V to 5.5V supply and feature thermal-overload and output short-circuit protection. Devices are specified over the -40C to +85C extended temperature range.
Features
o Microsoft Windows Vista Compliant o Class AB 2W Stereo BTL Speaker Amplifier o 100mW DirectDrive Headphone Amplifier Eliminates Costly, Bulky DC-Blocking Capacitors o Excellent RF Immunity o Integrated 120mA LDO (MAX9789A) o High +90dB PSRR, Low 0.002% THD+N o Low-Power Shutdown Mode o Click-and-Pop Suppression o Short-Circuit and Thermal-Overload Protection o 8kV ESD-Protected Headphone Driver Outputs o Available in 32-Pin Thin QFN (5mm x 5mm x 0.8mm) Package
MAX9789A/MAX9790A
Ordering Information
PART MAX9789AETJ+ MAX9790AETJ+ PIN-PACKAGE 32 Thin QFN-EP* 32 Thin QFN-EP* INTERNAL LDO Yes No PKG CODE T3255N-1 T3255N-1
Note: All devices are specified over the -40C to +85C extended temperature range. +Denotes lead-free package. *EP = Exposed paddle.
Simplified Block Diagrams
SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 3.0V TO 5.5V
SPKR_INR
MAX9789A
SPKR_INL
Applications
HP_INR
Notebook Computers Tablet PCs
HP_INL
Portable Multimedia Players
SPKR_EN HP_EN MUTE GAIN1 GAIN2 4.5V TO 5.5V LDO 1.21V TO 4.75V
Pin Configurations appear at end of data sheet.
U.S. Patent # 7,061,327
Windows Vista is a trademark of Microsoft Corp.
Simplified Block Diagrams continued at end of data sheet.
1
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VDD, PVDD, HPVDD, CPVDD to GND) ..................................................-0.3V to +6.0V GND to PGND, CPGND ......................................................0.3V CPVSS, C1N, VSS to GND......................................-6.0V to +0.3V HPR, HPL to GND ...............................................................3.0V Any Other Pin .............................................-0.3V to (VDD + 0.3V) Duration of OUT_+, OUT_- Short Circuit to GND or PVDD ......................................................Continuous Duration of Short Circuit between OUT_+, OUT_and LDO_OUT.........................................................Continuous Duration of Short Circuit between HPR, HPL and GND, VSS or HPVDD ..........................................................Continuous Continuous Current (PVDD, OUT_+, OUT_-, PGND).............1.7A Continuous Current (CPVDD, C1N, C1P, CPVSS, PVSS, VDD, HPVDD, LDO_OUT, HPR, HPL) .............................850mA Continuous Input Current (all other pins) .........................20mA Continuous Power Dissipation (TA = +70C) 32-Pin Thin QFN Single-Layer Board (derate 18.6mW/C above +70C) ..............................1489mW 32-Pin Thin QFN Multilayer Board (derate 24.9 mW/C above +70C) .............................1990mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
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
(VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER GENERAL Supply Voltage Headphone Supply Voltage VDD, PVDD CPVDD, HPVDD Guaranteed by PSRR and LDO Line Regulation Tests Guaranteed by PSRR Test SPKR_EN 1 (MAX9789A) Quiescent Current IDD 1 (MAX9790A) 1 0 0 Shutdown Current Bias Voltage Shutdown to Full Operation Gain Switching Time Channel-to-Channel Gain Tracking SPEAKER AMPLIFIER Output Power Total Harmonic Distortion Plus Noise Power-Supply Rejection Ratio POUT THD+N THD+N = 1%, f = 1kHz, TA = +25C RL = 8, POUT = 1W, f = 1kHz RL = 4, POUT = 1W, f = 1kHz VDD = 4.5V to 5.5V, TA = +25C PSRR f = 1kHz, 200mVP-P (Note 3) f = 10kHz, 200mVP-P (Note 3) 72 RL = 4 RL = 8 2 1 0.002 0.004 90 70 50 dB W % ISHDN VBIAS tSON tSW HP_EN 0 (MAX9789A) 0 (MAX9790A) 1 0 1 1.7 0.1 0.3 7 14 18 0.3 1.8 100 10 0.1 0.16 6 13 29 40 6 1.9 A V ms s dB mA mA A 4.5 3.0 5.5 5.5 V V SYMBOL CONDITIONS MIN TYP MAX UNITS
SPKR_EN = VDD, HP_EN = LDO_EN = GND
2
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER SYMBOL GAIN1 0 Voltage Gain AV 0 1 1 GAIN1 Input Impedance RIN 0 0 1 1 Output Offset Voltage VOS CONDITIONS GAIN2 0 1 0 1 GAIN2 0 1 0 1 80 65 45 25 1 -50 dBV -50 102 99 30 200 -70 1.4 RL = 16 RL = 32 100 55 -77 0.02 0.03 -94 dB FS dB VRMS pF dB V/s 15 mV k 6 10 15.6 21.6 dB MIN TYP MAX UNITS
MAX9789A/MAX9790A
Measured at speaker amplifier inputs
Measured between OUT_+ and OUT_-, TA = +25C RL = 8, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 2, 3) Out of shutdown RL = 8, POUT = 1W BW = 22Hz to 22kHz No sustained oscillations L to R, R to L, RL = 8, FS = 0.707VRMS, VOUT = 70.7nVRMS, 20kHz AES17, BW = 20Hz to 20kHz A-weighted f = 22Hz to 22kHz
Click-and-Pop Level
KCP
Signal-to-Noise Ratio Noise Capacitive-Load Drive Crosstalk Slew Rate HEADPHONE AMPLIFIER Output Power
SNR Vn CL
SR
POUT
THD+N = 1%, f = 1kHz, TA = +25C
mW
RL = 32, FS = 0.300VRMS, VOUT = 210mVRMS, 20kHz AES17, BW = 20Hz to 20kHz Total Harmonic Distortion Plus Noise THD+N RL = 32, POUT = 40mW, f = 1kHz RL = 16, POUT = 60mW, f = 1kHz RL = 10k, FS = 0.707VRMS, VOUT = 500mVRMS, 20kHz AES17, BW = 20Hz to 20kHz
dB FS
%
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3
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER Power-Supply Rejection Ratio (Note 5) Voltage Gain Input Impedance Output Offset Voltage Click-and-Pop Level SYMBOL PSRR AV RIN VOS KCP Measured at headphone amplifier inputs TA = +25C RL = 32, peak voltage, Into shutdown A-weighted, 32 samples per second (Notes 2, 3) Out of shutdown RL = 32, f = 1kHz, A-weighted, FS = 0.300VRMS, VOUT = 300VRMS RL = 10k, f = 1kHz, A-weighted, FS = 0.707VRMS, VOUT = 707VRMS RL = 32, POUT = 60mW BW = 22Hz to 22kHz No sustained oscillations RL = 32, FS = 0.300VRMS, VOUT = 30mVRMS RL = 10k, FS = 0.707VRMS, VOUT = 70.7mVRMS 22Hz to 22kHz A-weighted 20 CONDITIONS HPVDD = 3V to 5.5V, TA = +25C f = 1kHz, VRIPPLE = 200mVP-P (Note 3) f = 10kHz, VRIPPLE = 200mVP-P (Note 3) MIN 70 TYP 95 84 63 3.5 40 2 -60 dBV -60 89 dB FS 97 100 103 12 200 -74 dB -77 0.4 Human Body Model (HPR, HPL) 500 Inferred from line regulation IOUT = 0mA IOUT = 120mA VOUT = 4.75V, f = 1kHz, speaker POUT = 2W IOUT = 1mA 1.21 VSET 1.19 1.21 200 ISET VDO VOUT = 4.75V (fixed output operation), TA = +25C IOUT = 50mA IOUT = 120mA 20 25 75 500 50 mV 150 4.5 0.1 -40 120 -88 1.5 4.75 1.23 8 550 600 5.5 0.16 V/s kV kHz V mA mA dB % V V mV nA dB VRMS pF 80 7 dB k mV dB MAX UNITS
Dynamic Range
DR
Signal-to-Noise Ratio Noise Capacitive-Load Drive
SNR Vn CL
Crosstalk
L to R, R to L, 20kHz AES17 BW = 20Hz to 20kHz
Slew Rate ESD Charge-Pump Frequency Regulator Input Voltage Range Ground Current Output Current Crosstalk Fixed Output Voltage Accuracy Adjustable Output Voltage Range LDO_SET Reference Voltage LDO_SET Dual-Mode Threshold LDO_SET Input Bias Current (Note 4) Dropout Voltage (Note 5)
SR ESD fOSC VDD IGND IOUT
LOW-DROPOUT LINEAR REGULATOR
4
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN (MAX9789A only) = +5V, GND = PGND = CPGND = LDO_SET (MAX9789A only) = 0V, ILDO_OUT (MAX9789A only) = 0, C1 = C2 = CBIAS = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 5V (AVSP = 10dB, AVHP = 3.5dB), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER Current Limit Startup Time Line Regulation Load Regulation Ripple Rejection Output Voltage Noise VIN = 4.5V to 5.5V, LDO_OUT = 2.5V, ILDO_OUT = 1mA VLDO_OUT = 4.75V, 1mA < ILDO_OUT < 120mA VRIPPLE = 200mVP-P ILDO_OUT = 10mA f = 1kHz f = 10kHz -4.8 SYMBOL ILIM CONDITIONS MIN TYP 300 20 +0.8 0.2 59 42 125 +4.8 MAX UNITS mA s mV/V mV/mA dB VRMS
MAX9789A/MAX9790A
20Hz to 22kHz, CLDO_OUT = 2 x 1F, ILDO_OUT = 120mA VINH VINL 2
DIGITAL INPUTS (SPKR_EN, HP_EN, MUTE, GAIN1, GAIN2, LDO_EN (MAX9789A Only)) Input-Voltage High Input-Voltage Low Input Bias Current V 0.8 1 V A
Note 1: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design. Note 2: Specified at room temperature with an 8 resistive load connected across BTL output for speaker amplifier. Specified at room temperature 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 control pins, respectively. Note 3: Amplifier inputs AC-coupled to GND. Note 4: Maximum value is due to test limitations. Note 5: VLDO_OUT = VLDO_OUTNOMINAL - 2%.
Typical Operating Characteristics
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc01
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc02
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE)
RL = 10k 1 THD+N (%) fIN = 20Hz 0.1 fIN = 10kHz
MAX9789A toc03
-60 FS = 0.707VRMS VOUT = -3dB FS RL = 10k
-60 HPVDD = 3V FS = 0.707VRMS VOUT = -3dB FS RL = 10k
10
-70 THD+N (dB FS)
-70 THD+N (dB FS)
-80
-80
-90
-100
-90
0.01 fIN = 1kHz
-110 10 100 1k FREQUENCY (Hz) 10k 100k
-100 10 100 1k FREQUENCY (Hz) 10k 100k
0.001 0 0.5 1.0 1.5 2.0 OUTPUT VOLTAGE (VRMS)
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5
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE (HEADPHONE MODE)
MAX9789A toc04
CROSSTALK vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc05
HEADPHONE OUTPUT SPECTRUM
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 0 5k 10k FREQUENCY (Hz) FS = 0.300VRMS VOUT = -60dB FS RL = 10k
MAX9789A toc06 MAX9789A toc12 MAX9789A toc09
10
HPVDD = 3V RL = 10k
0 -10 -20 CROSSTALK (dB) -30 -40 -50 -60 -70 LEFT TO RIGHT FS = 0.707VRMS VOUT = -20dB FS RL = 10k
1 THD+N (%) fIN = 20Hz 0.1 fIN = 10kHz
0.01 fIN = 1kHz 0.001 0 0.5 1.0 1.5 2.0 OUTPUT VOLTAGE (VRMS)
-80 -90 -100 10 100 1k FREQUENCY (Hz) 10k 100k RIGHT TO LEFT
CROSSTALK (dB)
15k
20k
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE)
MAX9789A toc07
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE)
MAX9789A toc08
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (SPEAKER MODE)
-75 -80 -85 VOUT = -3dB FS
-75 VOUT = -3dB FS -80 THD+N (dB FS)
-75
-80 THD+N (dB FS)
VOUT = -3dB FS
-85
-85
THD+N (dB FS)
-90 -95 -100
-90
-90
-95 FS = 0.707VRMS RL = 3 -100 10 100 1k FREQUENCY (Hz) 10k 100k
-95 FS = 0.707VRMS RL = 4 10 100 1k FREQUENCY (Hz) 10k 100k -105 -110 10 100 1k FREQUENCY (Hz) 10k 100k FS = 0.707VRMS RL = 8
-100
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE)
MAX9789A toc10
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE)
RL = 4
MAX9789A toc11
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (SPEAKER MODE)
10 RL = 8
10 RL = 3 1 THD+N (%)
10
1 THD+N (%) THD+N (%)
1
0.1
fIN = 10kHz
0.1
fIN = 10kHz
0.1
fIN = 10kHz fIN = 20Hz fIN = 1kHz
0.01 fIN = 20Hz 0.001 0 0.5 1.0 1.5 2.0 2.5 3.0 OUTPUT POWER (W) fIN = 1kHz
0.01
0.01
0.001 0
fIN = 20Hz 0.5 1.0 1.5
fIN = 1kHz 2.0 2.5
0.001 0 0.5 1.0 1.5 OUTPUT POWER (W)
OUTPUT POWER (W)
6
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
CROSSTALK vs. FREQUENCY (SPEAKER MODE)
MAX9789A toc13
MAX9789A/MAX9790A
SPEAKER OUTPUT SPECTRUM
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 0 5k
MAX9789A toc14
OUTPUT POWER vs. LOAD RESISTANCE (SPEAKER MODE)
fIN = 1kHz
MAX9789A toc15
0 -10 -20 CROSSTALK (dB) -30 -40 -50 -60 -70 -80 -90 -100 10 100 1k FREQUENCY (Hz) 10k LEFT TO RIGHT RIGHT TO LEFT FS = 0.707VRMS VOUT = -20dB FS RL = 8
3.5 3.0 OUTPUT POWER (W) 2.5 2.0 1.5 1.0 THD+N = 1% 0.5 0 THD+N = 10%
FS = 0.707VRMS VOUT = -60dB FS RL = 8
100k
CROSSTALK (dB)
10k 15k FREQUENCY (Hz)
20k
1
10 RL ()
100
POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (SPEAKER MODE)
MAX9789A toc16
POWER-SUPPLY REJECTION RATIO (SPEAKER MODE)
-10 -20 -30 VRIPPLE = 200mVP-P OUTPUT REFERRED
MAX9789A toc17
1.50 POWER DISSIPATION PER CHANNEL (W) fIN = 1kHz 1.25 1.00 RL = 4 0.75 0.50 0.25 0 0 0.5 1.0 1.5 OUTPUT POWER PER CHANNEL (W) RL = 8
0
PSRR (dB) 2.0
-40 -50 -60 -70 -80 -90 100 10 100 1k 10k FREQUENCY (Hz) 100k
SPEAKER STARTUP WAVEFORM
MAX9789A toc18
SPEAKER SHUTDOWN WAVEFORM
MAX9789A toc19
SPKR_EN 5V/div OUT_+ AND OUT_2V/div
SPKR_EN 5V/div OUT_+ AND OUT_2V/div
OUT_+ - OUT_100mV/div
OUT_+ - OUT_100mV/div
20ms/div
20ms/div
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7
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc20
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc21
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
-70 -75 THD+N (dB FS) -80 -85 -90 -95 VOUT = -3dB FS
MAX9789A toc22
-65 -70 -75 THD+N (dB FS) -80 -85 -90 -95 -100 -105 -110 10 FS = 0.300VRMS RL = 32 100 1k FREQUENCY (Hz) 10k VOUT = -3dB FS
-65 -70 -75 THD+N (dB FS) -80 -85 -90 -95 -100 -105 -110 HPVDD = 3V FS = 0.300VRMS RL = 32 10 100 1k FREQUENCY (Hz) 10k VOUT = -3dB FS
-65
-100 -105 -110 100k 10 FS = 0.300VRMS RL = 16 100 1k FREQUENCY (Hz) 10k 100k
100k
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (HEADPHONE MODE)
MAX9789A toc23
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789A toc24
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789A toc25
-65 -70 -75 THD+N (dB FS) -80 VOUT = -3dB FS
10
10
1 THD+N (%)
f = 10kHz THD+N (%)
1 f = 1kHz
f = 10kHz
-85 -90 -95 -100 -105 -110 10 HPVDD = 3V FS = 0.300VRMS RL = 16 100 1k FREQUENCY (Hz) 10k 100k
f = 20Hz 0.1 f = 1kHz
0.1
f = 20Hz
0.01 0 50 100 OUTPUT POWER (mW)
RL = 16 150 200
0.01 0 20 40 60 OUTPUT POWER (mW)
RL = 32 80 100
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789A toc26
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789A toc27
CROSSTALK vs. FREQUENCY (HEADPHONE MODE)
-10 -20 -30 CROSSTALK (dB) -40 -50 -60 -70 -80 -90 LEFT TO RIGHT FS = 0.300VRMS VOUT = -20dB FS RL = 32
MAX9789A toc28
10
10
0
f = 10kHz 1 THD+N (%) f = 20Hz THD+N (%) f = 1kHz 1 f = 20Hz f = 10kHz
0.1
0.1
f = 1kHz
0.01 0 50 100
HPVDD = 3V RL = 16 150 OUTPUT POWER (mW)
0.01 0 20 40 60 OUTPUT POWER (mW)
HPVDD = 3V RL = 32 80 100
-100 -110 10 100
RIGHT TO LEFT 1k FREQUENCY (Hz) 10k 100k
8
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
HEADPHONE OUTPUT SPECTRUM
0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 0 5 10 FREQUENCY (kHz)
MAX9789A toc29
MAX9789A/MAX9790A
OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE)
MAX9789A toc30
OUTPUT POWER vs. LOAD RESISTANCE (HEADPHONE MODE)
HPVDD = 3V fIN = 1kHz OUTPUT POWER (mW)
MAX9789A toc31 MAX9789A toc34
150 fIN = 1kHz
100
FS = 0.707VRMS VOUT = -60dB FS RL = 32
OUTPUT POWER (mW)
AMPLITUDE (dB)
100 THD+N = 10% 50
THD+N = 10% 50
THD+N = 1% THD+N = 1% 0 15 20 10 100 RL () 1000 0 10 100 RL () 1000
POWER DISSIPATION vs. OUTPUT POWER (HEADPHONE MODE)
MAX9789A toc32
POWER DISSIPATION PER CHANNEL vs. OUTPUT POWER (HEADPHONE MODE)
POWER DISSIPATION PER CHANNEL (mW) HPVDD = 3V 100
MAX9789A toc33
HEADPHONE OUTPUT POWER vs. HPVDD
125 HEADPHONE OUTPUT POWER (mW)
POWER DISSIPATION PER CHANNEL (mW)
300 275 250 225 200 175 150 125 100 75 50 25 0 0 25 50 75 100 OUTPUT POWER PER CHANNEL (mW)
125
100 RL = 16 75
RL = 16
75 RL = 16 50 RL = 32
50 RL = 32 THD+N = 1% fIN = 1kHz 0 3.0 3.5 4.0 HPVDD (V) 4.5 5.0
RL = 32
25
25
0 125 0 20 40 60 OUTPUT POWER PER CHANNEL (mW) 80
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (HEADPHONE MODE)
-10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 -100 10 100 1k 10k FREQUENCY (Hz) 100k VRIPPLE = 200mVP-P OUTPUT REFERRED
MAX9789A toc35
HEADPHONE STARTUP WAVEFORM
MAX9789A toc36
HEADPHONE SHUTDOWN WAVEFORM
MAX9789A toc37
0
HP_EN 5V/div
HP_EN 5V/div
HP_ 500mV/div
HP_ 500mV/div
20ms/div
20ms/div
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9
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX9789A toc38
SHUTDOWN CURRENT vs. SUPPLY VOLTAGE
SPKR_EN = 5V HP_EN = 0 LDO_EN = 0 (MAX9789A) 0.2
MAX9789A toc39
20
0.3
10
SPKR_EN = 0 HP_EN = 1
SPKR_EN = 0 HP_EN = 0 SPKR_EN = 1 HP_EN = 0
5 SPKR_EN = 1 HP_EN = 1 0
SHUTDOWN CURRENT (A)
15 SUPPLY CURRENT (mA)
0.1
-5 4.50 4.75 5.00 5.25 SUPPLY VOLTAGE (V) 5.50
0 4.50 4.75 5.00 5.25 SUPPLY VOLTAGE (V) 5.50
LDO OUTPUT VOLTAGE ACCURACY vs. ILOAD
MAX9789A toc40
LDO OUTPUT VOLTAGE ACCURACY vs. AMPLIFIER OUTPUT POWER
LDO OUTPUT VOLTAGE ACCURACY (%) VLDO_OUT = 4.75V ILDO_OUT = 0A 0.05
MAX9789A toc41
2.0 VLDO_OUT = 4.75V LDO OUTPUT VOLTAGE ACCURACY (%) 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 0 25 50 75 100 ILOAD (mA) 125
0.10
0
-0.05
-0.10 150 0 0.5 1.0 1.5 2.0 2.5 AMPLIFIER OUTPUT POWER (W) 3.0
LDO OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE
LDO OUTPUT VOLTAGE ACCURACY (%) ILDO_OUT = 1mA 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -40 -15 10 35 TEMPERATURE (C) 60 85
MAX9789A toc42
DROPOUT VOLTAGE vs. ILOAD
90 DROPOUT VOLTAGE (mV) 80 70 60 50 40 30 20 10 0 0 25 50 75 ILOAD (mA) 100 125 150 VLDO_OUT = 3.3V VLDO_OUT = 4.75V
MAX9789A toc43
2.0
100
10
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Typical Operating Characteristics (continued)
(VDD = PVDD = CPVDD = HPVDD = LDO_EN = +5V, GND = PGND = CPGND = LDO_SET = 0V, C1 = C2 = CBIAS = CIN = 1F. RL = , unless otherwise specified, GAIN1 = 0, GAIN2 = 1 (AVSP = 10dB, AVHP = 3.5dB), measurement BW = 20kHz AES17, TA = +25C, unless otherwise noted. Headphone mode: SPKR_EN = 1, HP_EN = 0. Speaker mode: SPKR_EN = 0, HP_EN = 1.)
RIPPLE REJECTION vs. FREQUENCY
MAX9789A toc44
MAX9789A/MAX9790A
OUTPUT NOISE vs. FREQUENCY
MAX9789A toc45
0 -10 -20 RIPPLE REJECTION (dB) -30 -40 -50 -60 -70 -80 -90 10 100 1k VLDO_OUT = 4.75V
VRIPPLE = 200mVP-P IOUT = 10mA OUTPUT REFERRED
10
OUTPUT NOISE (VHz) 10k
1
0.1
VLDO_OUT = 3.3V 0.01 100k 10 100 1k FREQUENCY (Hz) 10k 100k FREQUENCY (Hz)
LINE-TRANSIENT RESPONSE
MAX9789A toc46
LDO LOAD-TRANSIENT RESPONSE
MAX9789A toc47
VDD 1V/div 5.5V 4.5V ILDO_OUT 15mA/div
LDO_OUT (AC-COUPLED) 20mV/div
AC-COUPLED VLDO_OUT 10mV/div
1ms/div
20ms/div
LDO SHUTDOWN RESPONSE
MAX9789A toc48
LDO CROSSTALK vs. FREQUENCY
-30 LDO_EN 2V/div CROSSTALK (dB) -40 -50 -60 -70 -80 -90 -100 -110 -120 LEFT SPEAKER TO LDO 10 100 1k 10k FREQUENCY (Hz) 100k RIGHT SPEAKER TO LDO VLDO_OUT = 4.75V POUT = 2W RL = 4 ILOAD = 0mA
MAX9789A toc49
ILOAD = 0mA
-20
VLDO_OUT 2V/div
200ms/div
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11
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Pin Description
PIN NAME MAX9789A MAX9790A 1 2 3 4 5, 21 6 7 8, 18 9 10 11 12 13 14 15 16 17 19 20 22 23 24 25 26 27 28 29 30 31 32 -- EP -- 2 3 -- 5, 21 6 7 8, 18 9 10 11 12 13 14 15 16 17 19 20 22 23 24 25 26 27 4, 28 -- 30 31 32 1, 29 EP LDO_SET Regulator Feedback Input. Connect to GND for 4.75V fixed output. Connect to a resistordivider for adjustable output. See Figure 1. Left-Channel Speaker Amplifier Input LDO Enable. Connect LDO_EN to VDD to enable the LDO. Power Ground. Star-connect to GND. Left-Channel Speaker Amplifier Output, Positive Phase Left-Channel Speaker Amplifier Output, Negative Phase Speaker Amplifier Power-Supply Input. Bypass with a 0.1F capacitor to PGND. Charge-Pump Power Supply. Connect a 1F capacitor between CPVDD and PGND. Charge-Pump Flying Capacitor Positive Terminal. Connect a 1F capacitor between C1P to C1N. Charge-Pump Ground. Connect directly to PGND plane. Charge-Pump Flying Capacitor Negative Terminal. Connect a 1F capacitor between C1P to C1N. Charge-Pump Output. Connect to PVSS. Headphone Amplifier Negative Power Supply. Connect a 1F capacitor between PVSS and PGND. Right-Channel Headphone Amplifier Output Left-Channel Headphone Amplifier Output Headphone Amplifier Positive Power Supply. Connect a 10F capacitor between HPVDD and PGND. Right-Channel Speaker Amplifier Output, Negative Phase Right-Channel Speaker Amplifier Output, Positive Phase Active-High Headphone Amplifier Enable Active-Low Speaker Amplifier Enable Common-Mode Bias Voltage. Bypass with a 1F capacitor to GND. Active-Low Mute Enable. Mutes speaker and headphone amplifiers. Right-Channel Headphone Amplifier Input Left-Channel Headphone Amplifier Input Signal Ground. Star-connect to PGND. LDO Output. Bypass with two 1F capacitors to GND. Positive Power Supply and LDO Input (MAX9789A). Bypass with one 0.1F capacitor and two 1F capacitors to GND (MAX9789A). Bypass with one 0.1F capacitor and one 1F capacitor to GND (MAX9790A). Speaker Amplifier Gain Select 1 Speaker Amplifier Gain Select 2 No Connection. Not internally connected. Exposed Paddle. Connect to GND. FUNCTION
SPKR_INR Right-Channel Speaker Amplifier Input SPKR_INL LDO_EN PGND OUTL+ OUTLPVDD CPVDD C1P CPGND C1N CPVSS PVSS HPR HPL HPVDD OUTROUTR+ HP_EN SPKR_EN BIAS MUTE HP_INR HP_INL GND LDO_OUT VDD GAIN1 GAIN2 N.C. EP
12
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Detailed Description
The MAX9789A/MAX9790A combine a 2W BTL speaker amplifier with an 100mW DirectDrive headphone amplifier. These devices feature comprehensive click-and-pop suppression and programmable four-level speaker amplifier gain control. The MAX9789A/MAX9790A feature high +90dB PSRR, low 0.002% THD+N, industry-leading clickand-pop performance, low-power shutdown mode, and excellent RF immunity. The MAX9789A incorporates an integrated LDO that serves as a clean power supply for a CODEC or other circuits. The MAX9789A/MAX9790A is Microsoft Windows Vista compliant. See Table 1 for a comparison of the Microsoft Windows Vista premium mobile specifications and MAX9789A/MAX9790A specifications. The speaker amplifiers use BTL architecture, doubling the voltage drive to the speakers and eliminating the need for DC-blocking capacitors. The output consists of two signals, identical in magnitude, but 180 out of phase. 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 a positive supply (CPVDD) 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 conserve board space and system cost, as well as improve low-frequency response. The MAX9789A/MAX9790A feature programmable speaker amplifier gain, allowing the speaker gain to be set by the logic voltages applied to GAIN1 and GAIN2, while the headphone amplifiers feature a fixed 3.5dB gain. Both 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, while the headphone amplifier outputs (IEC Air Discharge) can withstand 8kV ESD strikes. An additional feature of the speaker amplifiers is that there is no phase inversion from input to output.
MAX9789A/MAX9790A
Low-Dropout Linear Regulator (MAX9789A Only)
The MAX9789A's low-dropout (LDO) linear 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 = VDD to enable the LDO or set LDO_EN = GND to disable the LDO. The LDO is capable of providing up to 120mA continuous current and features Maxim's Dual ModeTM feedback, easily enabling a fixed 4.75V output or a user-adjustable output. When LDO_SET is connected to GND, the output is internally set to 4.75V. The output voltage can be adjusted from 1.21V to 4.75V by connecting two external resistors as a voltage divider, at LDO_SET (Figure 1).
Table 1. Windows Premium Mobile Vista Specifications vs. MAX9789A/MAX9790A Specifications
DEVICE TYPE REQUIREMENT THD+N Analog Line Output 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 [20Hz, 20kHz] -80dB FS, A-weighted -50dB [20Hz, 20kHz] -45dB FS [20Hz, 20kHz] -60dB FS, A-weighted -50dB [20Hz, 20kHz] MAX9789A/MAX9790A TYPICAL PERFORMANCE -94dB FS [20Hz, 20kHz] -97dB FS, A-weighted -77dB [20Hz, 20kHz] -77dB FS [20Hz, 20kHz] -89dB FS, A-weighted -74dB [20Hz, 20kHz]
Note: THD+N, DR, FREQUENCY ACCURACY, and CROSSTALK should be measured in accordance with AES-17 audio measurements standards. Dual Mode is a trademark of Maxim Integrated Products, Inc.
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
The output voltage is set by the following equation: R1 VLDO _ OUT = VLDO _ SET 1 + R2 where VLDO_SET = 1.21V. To simplify resistor selection: VLDO _ OUT R1 = R2 -1 1.21 Since the input bias current at LDO_SET is typically less than 500nA (max), large resistance values can be used for R1 and R2 to minimize power consumption without compromising accuracy. The parallel combination of R1 and R2 should be less than 1M. capacitors. Instead of two large capacitors (330F typically required to meet Vista magnitude response specifications), the MAX9789A/MAX9790A charge pump requires only two small 1F ceramic capacitors, conserving board space, reducing cost, and improving the low-frequency response of the headphone amplifier. Previous attempts to eliminate the output coupling capacitors involved biasing the headphone return (sleeve) to the DC bias voltage of the headphone amplifiers. This method raised some issues: * The sleeve is typically grounded to the chassis. Using this biasing approach, the sleeve must be isolated from system ground, complicating product design. * During an ESD strike, the amplifier's ESD structures are the only path to system ground. The amplifier must be able to withstand the full ESD strike. * When using the headphone jack as a line out to other equipment, the bias voltage on the sleeve may conflict with the ground potential from other equipment, resulting in large ground loop current and possible damage to the amplifiers.
DirectDrive
Conventional single-supply headphone amplifiers have their outputs biased about a nominal DC voltage (VDD / 2) for maximum dynamic range. Large coupling capacitors are needed to block this DC bias from the headphones. 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. It allows the MAX9789A/MAX9790A headphone amplifier output to be biased about GND. With no DC component, there is no need for the large DC-blocking
Low-Frequency Response In addition to the cost and size disadvantages, the DCblocking capacitors limit the low-frequency response of the amplifier and distort the audio signal: * The impedance of the headphone load and the DCblocking capacitor form a highpass filter with the -3dB point determined by:
f - 3dB = 1 2RLCOUT
LDO_OUT
R1
1F
1F
MAX9789A
LDO_SET
R2 GND
where RL is the impedance of the headphone and COUT is the value of the DC-blocking capacitor. * The highpass filter is required by conventional singleended, single-supply headphone amplifier to block the midrail DC component of the audio signal from the headphones. Depending on the -3dB point, the filter can attenuate low-frequency signals within the audio band. Larger values of COUT reduce the attenuation, but are physically larger, more expensive capacitors. Figure 2 shows the relationship between the size of COUT and the resulting low-frequency attenuation. Note the Vista's magnitude response specification calls for a -3dB point at 20Hz at the headphone jack. The -3dB point at 20Hz for a 32 headphone requires a 330F blocking capacitor (Table 2).
Figure 1. Adjustable Output Using External Feedback Resistors.
14
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
LOW-FREQUENCY ROLLOFF (RL = 16)
0 -3 -6 ATTENUATION (dB) -9 -12 -15 -18 -21 -24 -27 -30 1 10 100 1k 10k 100k FREQUENCY (Hz) 0.0001 10 100 1k FREQUENCY (Hz) 10k 100k 220F 100F 33F DirectDrive THD+N (%) 330F 1 10
ADDITIONAL THD+N DUE TO DC-BLOCKING CAPACITORS
COUT = 100F RL = 16
0.1 TANTALUM 0.01
0.001 ALUM/ELEC
Figure 2. Low-Frequency Attenuation of Common DC-Blocking Capacitor Values
Figure 3. Distortion Contributed by DC-Blocking Capacitors
* The voltage coefficient of the capacitor, the change in capacitance due to a change in the voltage across the capacitor, distorts the audio signal. At frequencies around the -3dB point, this effect is maximized and the voltage coefficient appears as frequency-dependent distortion. Figure 3 shows the THD+N introduced by two different capacitor dielectrics. Note that around the -3dB point, THD+N increases dramatically. * The combination of low-frequency attenuation and frequency-dependent distortion compromises audio reproduction. DirectDrive improves low-frequency reproduction in portable audio equipment that emphasizes low-frequency effects, such as multimedia laptops, MP3, CD, and DVD players (See Table 2).
speed that minimizes noise generated by switching transients. Limiting the switching speed of the charge pump minimizes the di/dt noise caused by the parasitic bond wire and trace inductance.
BIAS
The MAX9789A/MAX9790A feature an internally generated, power-supply independent, common-mode bias voltage of 1.8V referenced to GND. BIAS provides both click-and-pop suppression and sets the DC bias level for the amplifiers. The BIAS pin should be bypassed to GND with a 1F capacitor. No external load should be applied to BIAS. Any load lowers the BIAS voltage, affecting the overall performance of the device.
Headphone and Speaker Amplifier Gain
The MAX9789A/MAX9790A feature programmable speaker amplifier gain, set by the logic voltages applied to pins GAIN1 and GAIN2. Table 3 shows the logic combinations that can be applied to pins GAIN1 and GAIN2 and their affects on the speaker amplifier gain. The headphone amplifier gain is fixed at 3.5dB.
Table 2. Low-Frequency Rolloff
COUT (F) 22 33 100 220 330* f-3dB (Hz) RL = 16 452 301 99 45 30 RL = 32 226 151 50 23 15 11
Table 3. MAX9789A/MAX9790A Programmable Gain Settings
MAX9789A/MAX9790A GAIN1 0 0 1 1 GAIN2 0 1 0 1 SPEAKER MODE GAIN (dB) 6 10 15.6 21.6 HEADPHONE MODE GAIN (dB) 3.5 3.5 3.5 3.5
470 21 *Vista requirement for 32 load.
Charge Pump The MAX9789A/MAX9790A feature a low-noise charge pump. The 550kHz switching frequency is well beyond the audio range, and does not interfere with the audio signals. The switch drivers feature a controlled switching
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15
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Speaker and Headphone Amplifier Enable
The MAX9789A/MAX9790A 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 time, SPKR_EN and HP_EN can be tied together allowing a single logic voltage to enable either the speaker or the headphone amplifier as shown in Figure 4.
MUTE
The MAX9789A/MAX9790A allow for the speaker and headphone amplifiers to be muted. By driving MUTE low, both the speaker and headphone amplifiers are muted. When muted, the speaker outputs remain biased at VDD / 2.
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 VDD / 2. Likewise, 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 headphone. Since the MAX9789A/MAX9790A do not require output-coupling capacitors, no audible transient occurs. Additionally, the MAX9789A/MAX9790A features extensive click-and-pop suppression that eliminates any audible transient sources internal to the device. The startup/shutdown waveform in the Typical Operating Characteristics shows that there are minimal spectral components in the audible range at the output.
Applications Information
BTL Speaker Amplifiers
The MAX9789A/MAX9790A feature speaker amplifiers designed to drive a load differentially, a configuration referred to as bridge-tied load (BTL). The BTL configuration (Figure 5) offers advantages over the singleended configuration, where one side of the load is connected to ground. Driving the load differentially doubles the output voltage compared to a singleended amplifier operating under similar conditions. The doubling of the output voltage yields four times the output power at the load. Since the differential outputs are biased at mid-supply, there is no net DC voltage across the load. This eliminates the need for DC-blocking capacitors required for single-ended amplifiers. These capacitors can be large, expensive, consume board space, and degrade low-frequency performance.
Shutdown
The MAX9789A/MAX9790A feature a low-power shutdown mode, drawing 0.3A of supply current. By disabling the speaker, headphone amplifiers and the LDO (for MAX9789A), the MAX9789A/MAX9790A enter lowpower shutdown mode. Set SPKR_EN to V DD and HP_EN and LDO_EN to GND to disable the speaker amplifiers, headphone amplifiers, and LDO, respectively.
Click-and-Pop Suppression
Speaker Amplifier The MAX9789A/MAX9790A speaker amplifiers feature Maxim's comprehensive, industry-leading click-andpop suppression. During startup, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device. When entering shutdown, the differential speaker outputs ramp to GND quickly and simultaneously.
+1
VOUT(P-P)
MAX9789A/MAX9790A
SINGLE CONTROL PIN SPKR_EN HP_EN -1 2 x VOUT(P-P)
VOUT(P-P)
Figure 4. Enabling Either the Speaker or Headphone Amplifier with a Single Control Pin
16
Figure 5. Bridge-Tied Load Configuration
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Mono Speaker Configuration
The MAX9789A stereo BTL Class AB speaker amplifier can be configured to drive a mono speaker. Rather than combining the CODEC's left- and right-input signals in a resistive network prior to one channel of the speaker amplifier input, the transducer itself can be connected to the BTL speaker amplifier output as shown in Figure 6. When compared to the resistive network implementation, the configuration in Figure 6 will: 1) Eliminate noise pickup by eliminating the highimpedance node at the CODEC's left- and rightsignal mixing point. SNR performance will be improved as a result. 2) Eliminate gain error by eliminating any resistive mismatch between the external resistance used to sum the left and right signals and the MAX9789A internal resistance.
Output Power (Speaker Amplifier)
The increase in power delivered by the BTL configuration directly results in an increase in internal power dissipation over the single-ended configuration. The maximum power dissipation for a given VDD and load is given by the following equation: PDISS(MAX) = 2VDD2 2RL
MAX9789A/MAX9790A
If the power dissipation for a given application exceeds the maximum allowed for a given package, either reduce VDD, increase load impedance, decrease the ambient temperature, or add heat sinking to the device. Large output, supply, and ground PC board traces improve the maximum power dissipation in the package. Thermal-overload protection limits total power dissipation in these devices. When the junction temperature exceeds +150C, the thermal-protection circuitry disables the amplifier output stage. The amplifiers are enabled once the junction temperature cools by +15C. This results in a pulsing output under continuous thermal-overload conditions as the device heats and cools.
Power Dissipation and Heat Sinking
Under normal operating conditions, the MAX9789A/ MAX9790A can dissipate a significant amount of power. The maximum power dissipation for each package is given in the Absolute Maximum Ratings section under Continuous Power Dissipation, or can be calculated by the following equation: PDISSPKG(MAX) = TJ(MAX) - TA JA
Power Supplies
The MAX9789A/MAX9790A have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. The speaker amplifiers are powered from PVDD. PVDD ranges from 4.5V to 5.5V. The headphone amplifiers are powered from HPVDD and PVSS. HPVDD is the positive supply of the headphone amplifiers and ranges from 3V to 5.5V. PVSS is the negative supply of the headphone amplifiers. Connect PVSS to CPV SS . The charge pump is powered by CPV DD . CPVDD ranges from 3V to 5.5V and should be the same potential as HPVDD. The charge pump inverts the voltage at CPVDD, and the resulting voltage appears at CPV SS . The internal LDO and the remainder of the device is powered by VDD.
where TJ(MAX) is +150C, TA is the ambient temperature, and JA is the reciprocal of the derating factor in C/W as specified in the Absolute Maximum Ratings section. For example, JA for the 32-pin TQFN-EP package is +40.2C/W for a multilayer PC board.
CODEC
SPKR_OUTL
CIN1 SPKR_INL
OUTL+ OUTL-
CIN1 SPKR_OUTR
MAX9789A
SPKR_INR OUTR+ OUTRHP_INL
Component Selection
Supply Bypassing The MAX9789A/MAX9790A have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. Speaker Amplifier Power-Supply Input (PVDD) The speaker amplifiers are powered from PVDD. PVDD ranges from 4.5V to 5.5V. Bypass PVDD with a 0.1F capacitor to PGND. Note additional bulk capacitance is required at the device if long input traces between PVDD and the power source are used.
17
CIN2 LINE_OUTR
CIN2 LINE_OUTL HP_INR
HPL HPR
Figure 6. Mono Signal Output Configuration for MAX9789A
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Headphone Amplifier Power-Supply Input (HPVDD and PVSS)
The headphone amplifiers are powered from HPVDD and PVSS. HPVDD is the positive supply of the headphone amplifiers and ranges from 3.0V to 5.5V. Bypass HPVDD with a 10F capacitor to PGND. PVSS is the negative supply of the headphone amplifiers. Bypass PVSS with a 1F capacitor to PGND. Connect PVSS to CPV SS . The charge pump is powered by CPV DD . CPVDD ranges from 3.0V to 5.5V and should be the same potential as HPVDD. Bypass CPVDD with a 1F capacitor to PGND. The charge pump inverts the voltage at CPVDD, and the resulting voltage appears at CPVSS. A 1F capacitor must be connected between C1N and C1P.
INPUT COUPLING CAPACITOR-INDUCED THD+N vs. FREQUENCY (HEADPHONE MODE)
-50 -55 -60 THD+N (dB FS) -65 -70 -75 -80 -85 -90 10 0805 25V X7R 10% 1F 1206 25 X7R 10% 1F VOUT = 3dB FS FS = 1VRMS RL = 32 100 FREQUENCY (Hz) 1000 0402 6.3V X5R 10% 1F 0603 10V X5R 10% 1F
Power Supply and LDO Input (VDD) The internal LDO and the remainder of the device is powered by V DD . V DD ranges from 4.5V to 5.5V. Bypass VDD with a 0.1F capacitor to GND and two 1F capacitors in parallel to GND. Note additional bulk capacitance is required at the device if long input traces between VDD and the power source are used. Input Filtering The input capacitor (CIN), in conjunction with the amplifier input resistance (RIN), forms a highpass filter that removes the DC bias from the incoming signal. The ACcoupling 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 2RINCIN
Figure 8. Input Coupling Capacitor-Induced THD vs. Frequency (Headphone Mode)
BIAS Capacitor BIAS is the output of the internally generated DC bias voltage. The BIAS bypass capacitor, CBIAS improves PSRR and THD+N by reducing power supply and other noise sources at the common-mode bias node, and also generates the clickless/popless, startup/shutdown DC bias waveforms for the speaker and headphone amplifiers. Bypass BIAS with a 1F capacitor to GND. 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.
RIN is the amplifier's internal input resistance value given in the Electrical Characteristics. 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, such as 1206-sized X7R ceramic capacitors. Capacitors with higher voltage coefficients result in increased distortion at low frequencies (see Figure 8).
18
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Output Capacitor (C2) The output capacitor value and ESR directly affect the ripple at CPVSS. Increasing the value of C2 reduces output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. Lower capacitance values can be used in systems with low maximum output power levels. CPVDD Bypass Capacitor (C3) The CPVDD bypass capacitor (C3) lowers the output impedance of the power supply and reduces the impact of the MAX9789A/MAX9790A's charge-pump switching transients. Bypass CPVDD with 1F, the same value as C1, and place it physically close to the CPVDD and CPGND pins.
Connect C2 and C3 to the PGND plane. Connect PVSS and CPVSS together at C2. Place the charge-pump capacitors (C1, C2, and C3) 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. 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 consumed in the trace. If power is delivered through a 10m trace, only 5mW is consumed in the trace. Large output, supply and GND traces also improve the power dissipation of the device. The MAX9789A/MAX9790A 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.
MAX9789A/MAX9790A
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 PC board. Route PGND and all traces that carry switching transients away from GND and the traces and components in the audio signal path.
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19
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Block Diagrams
4.5V TO 5.5V
0.1F PVDD 8, 18
MAX9789A
6 1.0F SPKR_INL 3 STEREO BTL AMPLIFIER 7 OUTL+ OUTL-
1.0F
SPKR_INR
2
20 19 24 TO HPVDD
OUTR+ OUTRBIAS 1.0F
1.0F
HP_INL HP_INR
27 16 26 TO PVSS HPL
1.0F
3V TO 5.5V
HP_EN MUTE SPKR_EN GAIN2 GAIN1
22 25 23 32 31 4 30 CHARGE PUMP LDO BLOCK 11 CPGND C1 1F CONTROL 17 9 10 HPVDD CPVDD C1P C3 10F 15 HPR
3V TO 5.5V
3V TO 5.5V 4.5V TO 5.5V LDO_EN VDD 1.0F 1.0F 0.1F LDO_SET 1
12
C1N
TO CODEC 1.0F 1.0F
LDO_OUT
29 28 GND 5, 21 PGND 14 PVSS C2 1.0F 13 CPVSS
LOGIC PINS CONFIGURED FOR: LDO_EN = 1, LDO ENABLED SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED MUTE = 1, MUTE DISABLED GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN
20
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Block Diagrams (continued)
4.5V TO 5.5V
MAX9789A/MAX9790A
0.1F VDD 30 PVDD 8, 18
0.1F
MAX9790A
6 1.0F SPKR_INL 3 STEREO BTL AMPLIFIER 7 OUTL+ OUTL-
1.0F
SPKR_INR
2
20 19 24 TO HPVDD
OUTR+ OUTRBIAS 1.0F
1.0F
HP_INL HP_INR
27 16 26 TO PVSS HPL
1.0F
3V TO 5.5V 15 HP_EN MUTE SPKR_EN GAIN2 GAIN1 22 25 23 32 31 CHARGE PUMP 11 CPGND CONTROL 17 9 10 HPVDD CPVDD C1P C3 10F HPR 3V TO 5.5V
C1 1F
12
C1N
4, 28 GND
5, 21 PGND
14 PVSS C2 1.0F
13 CPVSS
LOGIC PINS CONFIGURED FOR: SPKR_EN = 0, SPEAKER AMPLIFIERS ENABLED HP_EN = 1, HEADPHONE AMPLIFIER ENABLED MUTE = 1, MUTE DISABLED GAIN1 = 0 GAIN = 0, 6dB SPEAKER GAIN
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21
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
System Diagrams
5.0V 5.0V
0.1F
1F
1F
CBULK
10F
VLDO_OUT 1F SPKR_L SPKR_R HDA CODEC HP_R HP_L MONO DGND AGND C3 1F 5.0V CIN 1F CIN 1F CIN 1F CIN 1F
BIAS VDD
PVDD
HPVDD OUTL+ 4
SPKR_INL SPKR_INR
OUTL-
OUTR+ HP_INR HP_INL HPL 4 OUTR-
MAX9789A
CPVDD C1 1F C1P
HPR
LDO_SET C1N SPKR_EN HP_EN LDO_OUT 1F 1F
4.75V
C
LDO_EN GAIN1 GAIN2 MUTE GND PGND 12V CPVSS PVSS CPGND C2 1F
100F
1F
VDD FS2 FS1 G1 G2 SHDN OUT+ OUT8
MAX9713
0.47F IN+ 0.47F INSS 0.47F 0.01F REG PGND
C1P 0.1F C1N VDD 1F CHOLD
AGND
22
______________________________________________________________________________________
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
System Diagrams (continued)
+5V +3.3V
MAX9789A/MAX9790A
1F VLDO_OUT
1F
0.1F VDD PVDD HPVDD OUTL+
10F
1F SPKR_L 1F SPKR_R HDA CODEC HP1_R HP1_L +3.3V HP2_R CPVDD HP2_L DGND AGND C3 1F C1 1F C1P LDO_SET C1N SPKR_EN HP_EN C LDO_EN CPVSS GAIN2 GAIN1 MUTE GND PGND PVSS CPGND C2 1F LDO_OUT 1F 1F 4.75V SPKR_INR 1F HP_INR 1F HP_INL HPL HP1 OUTR+ OUTRSPKR_INL OUTL-
MAX9789A
HPR
SHDNR SHDNL
C1P 1F C1N
1F INR 1F INL +3.3V PVDD 1F SVDD
MAX4411
OUTL OUTR HP2
PVSS SVSS SGND PGND 1F
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23
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Pin Configurations
SPKR_EN SPKR_EN HP_EN OUTR+
TOP VIEW
BIAS
HP_EN
OUTR+
OUTR-
HPVDD
PGND
OUTR-
PGND
PVDD
24 MUTE 25 HP_INR 26 HP_INL 27 GND 28 LDO_OUT 29 VDD 30 GAIN1 31 GAIN2 32 1 LDO_SET
23
22
21
20
19
18
17 16 15 14 13 HPL HPR PVSS CPVSS C1N CPGND C1P CPVDD MUTE 25 HP_INR 26 HP_INL 27 GND 28 N.C. 29 VDD 30 GAIN1 31 GAIN2 32
24
23
22
21
20
19
18
PVDD
BIAS
17 16 15 14 13 HPL HPR PVSS CPVSS C1N CPGND C1P CPVDD
MAX9789A
12 11
MAX9790A
HPVDD 12 11 10 9 8 PVDD
+
2 SPKR_INR 3 SPKR_INL 4 LDO_EN 5 PGND 6 OUTL+
EP*
10 9
+
1 N.C. 2 SPKR_INR 3 SPKR_INL 4 GND 5 PGND 6 OUTL+
EP*
7 OUTL-
8 PVDD
7 OUTL-
TQFN
*EP = EXPOSED PADDLE *EP = EXPOSED PADDLE
TQFN
Simplified Block Diagrams (continued)
SPEAKER SUPPLY 4.5V TO 5.5V HEADPHONE SUPPLY 3.0V TO 5.5V
Chip Information
PROCESS: BiCMOS
MAX9790A
SPKR_INR
SPKR_INL
HP_INR
HP_INL SPKR_EN HP_EN MUTE GAIN1 GAIN2
24
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Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
MAX9789A/MAX9790A
______________________________________________________________________________________
QFN THIN.EPS
25
Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers MAX9789A/MAX9790A
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information 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.
26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

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