View PAM8403_4240092.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Key Features
n 3W Output at 10% THD with a 4 Load and 5V Power Supply n Filterless, Low Quiescent Current and Low EMI n Low THD+N n Superior Low Noise n Efficiency up to 90% n Short Circuit Protection n Thermal Shutdown n Few External Components to Save the Space and Cost n Pb-Free Package
General Description
The PAM8403 is a 3W, class-D audio amplifier. It offers low THD+N, allowing it to achieve highquality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, requiring no low-pass output filters,thus to save the system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8403 is much better than that of class-AB cousins. It can extend the battery life, ideal for portable applications. The PAM8403 is available in SOP-16 package.
Applications
n n n n n
LCD Monitors / TV Projectors Notebook Computers Portable Speakers Portable DVD Players, Game Machines Cellular Phones/Speaker Phones
Typical Application
Efficiency vs Output Power
100 90
VDD PVDD
80
Efficiency(%)
70 60 50 40 30 20 10 0 0 0.5 1 RL=4
RL=8
1F
1F
470F
1F 13
6
4
VDD
0.47F INL Ri 7
PVDD PVDD +OUT_L -OUT_L
1
INL
1.5 Output Pow er(W)
2
2.5
3
8 0.1F 0.47F 10 INR Ri 12 SHDN 5 MUTE
VREF
3
PAM8403
INR SHDN MUTE GND NC PGNDPGND
11 9 2 15
-OUT_R
14
Radiated Emissions
+OUT_R
16
FCC Class B Limit
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
1
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Block Diagram
VDD VDD/2
+
PVDD
PGND
INR
DRIVER MODULATOR
+OUT_R -OUT_R
THERMAL PROTECTION
ATTENUATION DECODER
INTERFACE CONTROL
MUTE
INTERNAL OSCILLATOR
BIAS AND REFERENCES
VREF
SHDN
OSC CURRENT PROTECTION
MODULATOR INL VDD/2
+
DRIVER
+OUT_L
-
-OUT_L
GND
PVDD
PGND
Pin Configuration & Marking Information
Top View SOP-16 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 X: Internal Code A: Assembly Code T: Testing Code Y: Year WW: Week LL: Internal Code
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
PAM8403 XATYWWLL
2
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Pin Descriptions
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Name +OUT_L PGND -OUT_L PVDD MUTE VDD INL VREF NC INR GND SHDN PVDD -OUT_R PGND +OUT_R Left Channel Positive Output Power GND Left Channel Negative Output Power VDD Mute Control Inputactive low Analog VDD Left Channel Input Internal analog reference, connect a bypass capacitor from VREF to GND No connect Right Channel Input Analog GND Shutdown Control Input (active low) Power VDD Right Channel Negative Output Power GND Right Channel Positive Output Description
These are stress ratings only and functional operation is not implied . Exposure to absolute maximum ratings for prolonged time periods may affect device reliability . All voltages are with respect to ground . Supply Voltage . ...........................................6.6V Input Voltage.............................-0.3V to V DD+0.3V Operation Temperature Range.........-40C to 85 C Maximum Junction Temperature..................150C Operation Junction Temperature.....-40 C to 125 C Storage Temperature.....................-65 C to 150 C Soldering Temperature....................... 300C, 5sec
Absolute Maximum Ratings
Recommended Operating Conditions
Supply voltage Range........................ 2.5V to 5.5V Max. Supply Voltage (for Max. duration of 30 minutes)................................................6.4V Operation Temperature Range.........-40 C to 85 C Junction Temperature Range.........-40 C to 125 C
Thermal Information
Parameter Thermal Resistance (Junction to Ambient) Thermal Resistance (Junction to Case) Symbol JA JC Package SOP-16 SOP-16 Maximum 110 23 Unit C/W C/W
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
3
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Electrical Characteristic
V DD=5V, Gain=24dB, R L=8 , T A=25 C , unless otherwise noted.
Symbol VIN Parameter Supply Power VDD=5.0V THD+N=10%,f=1kHz, RL =4 VDD=3.6V VDD=3.0V VDD=5.0V THD+N=1%,f=1kHz, RL =4 Po Output Power THD+N=10%,f=1kHz, RL =8 VDD=3.6V VDD=3.0V VDD=5.0V VDD=3.6V VDD=3.0V VDD=5.0V THD+N=1%,f=1kHz, RL =8 VDD=3.6V VDD=3.0V VDD=5.0V,Po=0.5W,RL=8 THD+N Total Harmonic Distortion Plus Noise VDD=3.6V,Po=0.5W,RL=8 VD D=5.0V,Po=1W,RL =4 VD D=3.6V,Po=1W,RL =4 Gv PSRR Cs SNR Vn Dyn Gain Power Supply Ripple Rejection Crosstalk Signal-to-noise ratio Output noise Dynamic range Efficiency VD D=5.0V, Inputs ac-grounded with CIN =0.47F VDD=5V,Po=0.5W,RL =8,Gv=20dB VDD=5V, Vorms=1V,Gv=20dB VDD=5V, Inputs ac-grounded with CIN =0.47F VDD=5.0V, THD=1% R L=8, THD=10% R L=4, THD=10% VDD=5.0V IQ Quiescent Current VDD=3.6V VDD=3.0V No load f=100Hz f=1kHz F=1kHz f=1kHz A-weighting No A-weighting f=1kHz f=1kHz f=1kHz f=1kHz Test Conditions MIN 2.5 3.2 1.6 1.3 2.5 1.3 0.85 1.8 0.9 0.6 1.4 0.72 0.45 0.15 0.11 0.15 0.11 24 -59 -58 -95 80 100 150 90 87 83 16 10 8 mA dB % dB dB V % dB dB % W W W W TYP MAX UNIT 5.5 V
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
4
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Electrical Characteristic (Continued)
V DD=5V Gain=24dB, R L=8 , T A=25 C , unless otherwise noted.
Symbol IMUT E ISD Rdson fsw Vos VIH VIL VIH VIL OTP OTH Parameter Muting Current Shutdown Current Static Drain-to-source On-state Resistor Switching Frequency Output Offset Voltage Enable Input High Voltage Enable Input Low Voltage MUTE Input High Voltage MUTE Input Low Voltage Over Temperature Protection Over Temperature Hysterisis Test Conditions VDD=5.0V VDD=2.5V to 5.5V IDS =500mA,Vgs=5V VDD=3V to 5V Vin=0V, VDD=5V VDD=5.0V VDD=5.0V VDD=5.0V VDD=5.0V No Load, Junction Temperature VDD=5V 1.5 1.5 VMUTE =0.3V Vsd=0.3V PMOS NMOS MIN TYP 3.5 <1 180 140 260 10 1.4 0.7 1.4 0.7 140 30 0.4 0.4 MAX UNIT mA A m kHz mV V
V
C
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
5
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Typical Operating Characteristics (T =25C)
A
1. THD+N vs Output Power
100 50
2. THD+N vs Output Power
100 50
20 10 5
V DD=3.3V V DD=2.5V
20 10 5
V DD=2.5V
V DD=3.3V
2 % 1 0.5
2 % 1 0. 5
0.2 0.1 0.05
0. 2 0. 1 0. 05
0.02 0.01 20m
V DD=5V
50m 100m 200m W 500m 1 2 4
V DD=5V
50 m 100 m 200 m W 500 m 1 2 4
0. 02 0. 01 20 m
R L=4 , Gain = 24dB, f=1kHz 3. THD+N vs Frequency
100 50
100 50
R L=8 , Gain = 24dB, f=1kHz 4. THD+N vs Frequency
20 10 5
20 10 5
2 % 1 0. 5
%
2 1 0.5
0. 2 0. 1 0. 05
L
0.2 0.1 0.05
L
0. 02 0. 01 20
0.02
R
50 100 200 500 Hz 1k 2k 5k 10k 20k
R
50 100 200 500 Hz 1k 2k 5k 10k 20k
0.01 20
V DD=5V, R L=4 ,Gain = 24dB, Cin=1 F
V DD=5V, R L=8 ,Gain = 24dB, Cin=1 F
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
6
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Typical Operating Characteristics (continued)
5. Frequency response
+0
6. Crosstalk VS Frequency
TTTTTTTT T TTT
-10 -20
+24 .4 +24 .2 +24 +23 .8 d B r A +23 .2 +23 +22 .8 +22 .6 10 20 50 +23 .6 +23 .4
L
-30
R
d B
-40 -50 -60 -70 -80 -90 -100
L
R
50 100 200 500 Hz 1k 2k 5k 10k 20k
100
200
500 Hz
1k
2k
5k
10 k
20 k
-110 20
V DD=5V, R L=8 ,Gain = 24dB, Cin=1 F
V DD=5V, R L=4 , Gv=24dB, Po=0.5W
7. Noise Floor FFT
+0 -10 -20 -30 -40 -50 d B V -60 -70 -80 -90 -100 -110 -120 20 +0 -10 -20 -30 -40 -50 -60 -70 d B V
L
-80 -90 -100 -110 -120
R
50 100 200 500 Hz 1k 2k 5k 10k 20k
Inputs ac-ground, V DD=5V, R L=8 ,Cin=1 F
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
7
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Application Notes
1. When the PAM8403 works with LC filters, it should be connected with the speaker before it's powered on, otherwise it will be damaged easily.
2. When the PAM8403 works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the possible electromagnetic interference. 3. The recommended operating voltage is 5.5V. When the PAM8403 is powered with 4 battery cells, it should be noted that the voltage of 4 new dry or alkaline batteries is over 6.0V, higher than its operation voltage, which will probably damage the device. Therefore, it's recommended to use either 4 Ni-MH (Nickel Metal Hydride) rechargeable batteries or 3 dry or alkaline batteries. 4. One should not make the input signal too large. Large signal can cause the clipping of output signal when increasing the volume. This will damage the device b ecause of big gain of the PAM8403 . 5. When testing the PAM8403 without LC filters by using resistor instead of speaker as the output load, the test results, e.g. THD or efficiency, will be worse than those of using speaker as load.
Test Setup for Performance Testing
PAM8403 Demo Board Load +OUT AP System One Generator Input AP Low Pass Filter GND -OUT VDD AUX-0025 AP System One Analyzer
Power Supply
Notes
1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer. 2. Two 22H inductors are used in series with load resistor to emulate the small speaker for efficiency measurement.
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
8
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Application Information
Maximum Gain As shown in block diagram (page 2), the PAM8403 has two internal amplifier stages. The first stage's gain is externally con figurable, while the second stage's is internally fixed. The closed-loop gain of the first stage is set by selecting the ratio of R f to R i while the second stage's gain is fixed at 2x.The output of amplifier 1 serves as the input to amplifier 2, thus the two amplifiers produce signals identical in magnitude, but different in phase by 180. Consequently, the differential gain for the IC is A VD=20*log [2*(R f/R i)] T h e PA M 8 4 0 3 s e t s m a x i m u m R f = 1 4 2 k , minimum R i=18k , so the maximum closed-gain is 24dB. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8403. A logic low on this pin disables the outputs, and a logic high on this pin enables the outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent current is listed in the electrical characteristic table. The MUTE pin can be left floating due to the internal pull-up. Shutdown operation In order to reduce power consumption while not in use, the PAM8403 contains shutdown circuitry to turn off the amplifier's bias circuitry. This shutdown feature turns the amplifier off when logic low is applied to the SHDN pin. By switching the SHDN pin connected to GND, the PAM8403 supply current draw will be minimized in idle mode. The SHDN pin can be left floating due to the internal pull-up. Power supply decoupling The PAM8403 is a high performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and PSRR as low as possible. Power supply decoupling affects low frequency response. Optimum decoupling is achieved by using two capacitors of different types targeting to different types of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-seriesresistance (ESR) ceramic capacitor, typically 1.0F, works best, placing it as close as possible to the device V DD terminal. For filtering lowerfrequency noise signals, a large capacitor of 20F (ceramic) or greater is recommended, placing it near the audio power amplifier. Input Capacitor (C i) Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low frequencies without severe attenu ation. But in many cases the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual system perfor mance. In this case, input capacitor (C i) and input resistance (R i) of the amplifier form a high-pass filter with the corner frequency determined by equation below, 1 fC= 2RiCi In addition to system cost and size, click and pop perfor mance is affected by the size of the input coupling capacitor, C i. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage (nominally 1/2 V DD). This charge comes from the internal circuit via the feedback and is apt to create pops upon device enable. Thus, by minimizing the capacitor size based on necessary low frequency response, turn-on pops can be minimized. Analog Reference Bypass Capacitor (C BYP) The Analog Reference Bypass Capacitor (C BYP) is the most critical capacitor and serves several important functions. During start-up or recovery from shutdown mode, C BYP determines the rate at which the amplifier starts up. The second function is to reduce noise caused by the power supply coupling into the output drive signal. This noise is from the internal analog reference to the amplifier, which appears as degraded PSRR and THD+N. A ceramic bypass capacitor (C BYP) with values of 0.47F to 1.0F is recommended for the best THD and noise performance. Increasing the bypass capacitor reduces clicking and popping noise from power on/off and entering and leaving shutdown.
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
9
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Under Voltage Lock-out (UVLO) The PAM8403 incorporates circuitry designed to detect low supply voltage. When the supply voltage drops to 2.0V or below, the PAM8403 outputs are disabled, and the device comes out of this state and starts to normal function when V DD 2.2V. Short Circuit Protection (SCP) The PAM8403 has short circuit protection circuitry on the outputs to prevent damage to the device when output-to-output or output-to-GND short occurs. When a short circuit is detected on the outputs, the outputs are disabled immediately. If the short was removed, the device activates again. Over Temperature Protection Thermal protection on the PAM8403 prevents the device from damage when the internal die temperature exceeds 140C. There is a 15 degree tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 30 C . This large hysteresis will prevent motor boating sound well and the device begins normal operation at this point without external system intervention.
Ferrite Bead
How to Reduce EMI (Electro Magnetic Interference) A simple solution is to put an additional capacitor 1000 F at power supply terminal for power line coupling if the traces from amplifier to speakers are short (<20cm). Most applications require a ferrite bead filter as shown in Figure 2. The ferrite filter reduces EMI of around 1 MHz and higher. When selecting a ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies.
Ferrite Bead
OUT+
220pF
OUT220pF
Figure 2: Ferrite Bead Filter to reduce EMI
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
10
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Ordering Information
PAM8403 X X
Shipping Package Package Type
Part Number PAM8403DR Marking PAM8403 XATYWWLL Package Type SOP-16 MOQ/Shipping Package 2,500 Units/Tape&Reel
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
11
PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Outline Dimension
SOP-16
A2
B D
A1
A
C
E1
E
L
e
Symbol A A1 A2 B C D E E1 e L
Dimensions Millimeters Min 1.350 0.100 1.350 0.330 0.190 9.800 3.800 5.800 1.270(TYP) 0.400 0 1.270 8 Max 1.750 0.250 1.550 0.510 0.250 10.000 4.000 6.300
Power Analog Microelectronics , Inc
www.poweranalog.com 09/2008 Rev 1.3
12

▲Up To Search▲

Price & Availability of PAM8403

	To Download PAM8403 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .