PAM8603MDET

PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control F eatures n 3W Output at 10% THD with a 4 Ω Load and 5V Power Supply n Filterless, Low Quiescent Current and Low EMI n Low THD+N n 64-Step DC Volume Control from -75dB to +24dB n Superior Low Noise n Efficiency up to 89% n Short Circuit Protection n Thermal Shutdown n Few External Components to Save the Space and Cost n Pb-Free Package General Description The PAM8603M is a 3W, sterero, class-D audio amplifier with DC volume control. It offers low THD+N, allowing it to produce high-quality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, requiring no low-pass output filters , which saves the system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8603M is much better than class-AB cousins. It can extend the battery life thus ideal for portable applications. The PAM8603M is available in SSOP-24 and SOP-18 packages. 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 Circuit Efficiency vs Output Power PVDDL 10μF 1μF Efficiency(%) 100 90 80 70 60 50 40 30 20 10 RL=4Ω RL=8Ω PVDDL +OUTL PGNDL +OUTR -OUTL 0.47μF INL 1μF VREF ON -OUTR 0.47 μF INR VDD VDD 1μF INR 0 0 0.5 1 1.5 Output Pow er(W) 2 2.5 3 INL PAM8603M Radiated Emissions SHDN SHDN ON VDC VOLUME GND 50kO MUTE MUTE FCC Class B Limit PVDDR PGNDR 1μF 10μF PVDDR Power Analog Microelectronics , Inc www.poweranalog.com 1 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Block Diagram VDD VDD/2 PVDDR PGNDR INR + + MODULATOR DRIVER +OUTR -OUTR THERMAL PROTECTION Attenuation Decoder VDC VOLUME MUTE SHDN Interface Control INTERNAL OSCILLATOR BIAS AND REFERENCES VREF OSC CURRENT PROTECTION MODULATOR +OUTL DRIVER INL VDD/2 + - + -OUTL GND PVDDL PGNDL Pin Configuration & Marking Information Top View SSOP-24 +OUTL PGNDL PGNDL -OUTL PVDDL 1 2 3 4 5 24 +OUTR 23 PGNDR 22 PGNDR 21 -OUTR 20 PVDDR 19 SHDN 18 GND 17 INR 16 NC 15 NC 14 V REF 13 NC Top View SOP-18 +OUTL PGNDL -OUTL PVDDL MUTE VDD INL VDC VOLUME 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 MUTE 6 VDD 7 INL 8 NC 9 VDC10 VOLUME 11 NC12 +OUTR PGNDR -OUTR PVDDR SHDN GND INR NC VREF PAM8603M XXXYWWXX Power Analog Microelectronics , Inc www.poweranalog.com 2 10/2008 Rev 1.0 PAM8603M XXXYWWXX X: Internal Code Y: Year WW: Week PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control P in Descriptions Pin Name +OUTL PGNDL -OUTL PVDDL MUTE VDD INL NC VDC VOLUME VREF INR GND SHDN PVDDR -OUTR PGNDR +OUTR SSOP-24 1 2,3 4 5 6 7 8 9, 12,13,15,16 10 11 14 17 18 19 20 21 22,23 24 SOP-18 1 2 3 4 5 6 7 11 8 9 10 12 13 14 15 16 17 18 Description Left Channel Positive Output Left Channel Power GND Left Channel Negative Output Left Channel Power Supply Mute Control Input（active low） Analog Power Supply Left Channel Input No Connect Analog reference for gain control section DC volume control to set the gain of Class-D Internal analog reference, connect a bypass capacitor from VREF to GND Right Channel Input Analog Ground Shutdown Control Input(active low) Right Channel Power Supply Right Channel Negative Output Right Channel Power GND Right Channel Positive Output Absolute Maximum Ratings 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 Maximum Junction Temperature..................150 °C Storage Temperature.....................-65°C to 150 °C Soldering Temperature...................... 300°C, 5sec Recommended Operating Conditions Supply Voltage Range....................... 2.8V to 5.5V Max. Supply Voltage (for Max. duration of 30 minutes)................................................6.4V Junction Temperature Range.........-40 °C to 125 °C Ambient Temperature Range............-40 °C to 85 °C Thermal Information Parameter Thermal Resistance (Junction to Ambient) Thermal Resistance (Junction to Case) Symbol θJA θJc Package SSOP-24 SOP-18 SSOP-24 SOP-18 Maximum 96 70 18 16 Unit °C/W °C/W °C/W °C/W Power Analog Microelectronics , Inc www.poweranalog.com 3 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Electrical Characteristic V DD=5V, Gain=20dB,T A=25 °C, unless otherwise noted. Symbol VDD Parameter Supply Voltage THD+N=10%, f=1kHz,RL=4Ω THD+N=1%, f=1kHz, RL=4Ω Po Output Power THD+N=10%, f=1kHz,RL=8Ω THD+N=1%,f=1kHz,R L=8Ω VDD =5.0V,Po=0.5W,RL=8Ω THD+N Total Harmonic Distortion Plus Noise VDD =3.6V,Po=0.5W,RL=8Ω VDD =5.0V,Po=1W,R L=4Ω VDD =3.6V,Po=1W,R L=4Ω PSRR Cs SNR Vn Dyn η Power Supply Ripple Rejection Crosstalk Signal-to-noise ratio Output noise Dynamic range Efficiency VDD =5.0V, Inputs ac-grounded f=100Hz f=1kHz f=1kHz V DD =5.0V V DD =3.6V V DD =5.0V V DD =3.6V V DD =5.0V V DD =3.6V V DD =5.0V V DD =3.6V f=1kHz Test Conditions MIN 2.8 2.85 1.55 2.35 1.25 1.55 0.75 1.15 0.5 3.2 1.8 2.6 1.5 1.8 0.9 1.4 0.72 0.15 0.11 0.15 0.11 -59 -58 -95 85 A-weighting No A-weighting 90 f=1kHz 85 80 No load 98 75 120 102 89 85 13.5 8.5 2.7 20 15 5 1 PMOS NMOS 200 240 180 260 10 1.45 0.65 135 30 °C 500 350 300 50 kHz mV V mA μA mΩ mA 150 300 dB % 0.3 0.25 0.3 0.25 -50 -50 -80 dB dB μV dB % % W W W TYP MAX UNIT 5.5 V W VDD =5V,Po=0.5W, R L=8Ω,f=1kHz VDD =5V, Vo_rms=1V, f=1kHz VDD =5V, Inputs ac-grounded with Cin=0.47μF VDD =5.0V, THD=1%, f=1kHz RL=8Ω, THD=10% RL=4Ω, THD=10% VDD =5V VDD =3.6V VDD =5.0V, V MUTE=0.3V VDD =2.5V to 5.5V, VS D=0.3V IDS =500mA,Vgs=5V VDD =3V to 5V Vin=0V, V DD =5V VDD =5V VDD =5V No Load, Junction Temperature, VDD=5V IQ IMUTE IS D Rdson fsw Vos VIH V IL OTP OTH Quiescent Current Muting Current Shutdown Current Static Drain-to-source On-state Resistor Switching Frequency Output Offset Voltage SD/MUTE Input High SD/MUTE Input Low Over Temperature Protection Over Temperature Hysterisis Power Analog Microelectronics , Inc www.poweranalog.com 4 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Typical Operating Characteristics (T =25°C) A 1. Efficiency VS Output Power 100 90 80 Efficiency (%) Efficiency (%) 100 90 80 2. Efficiency VS Output Power 70 60 50 40 30 20 10 0 0 V DD=5V V DD=3.6V 70 60 50 40 30 20 V DD=5V V DD=3.6V R L=8 Ω 0.5 1 Output Pow er (W) 1.5 2 10 0 0 0.5 1 1.5 2 Output Pow er (W) R L=4 Ω 2.5 3 3.THD+N VS Output Power 30 10 5 2 1 % 0.5 0.2 0.1 0.05 0.02 0.01 10m 20m 50m 100 m 200 m W 500 m 1 2 4 . 4.THD+N VS Output Power 30 20 10 5 R L=8 Ω Gain=20dB f=1kHz V DD=5V R L=4 Ω Gain=20dB f=1kHz V DD=5V 2 1 V DD=3.6V V DD=3.6V % 0.5 0.2 0.1 0 05 0.02 0.01 10 m 20 m 50 m 100m W 200m 500m 1 2 4 5. THD+N VS Frequency 10 10 6. THD+N VS Frequency 5 5 Po=0.5W R L=8 Ω Cin=0.47 μ F Gain=20dB 2 2 Po=1W R L=4 Ω Cin=0.47 μ F Gain=20dB % 1 % 1 0.5 V DD=5V 0.5 V DD=3.6V 0.2 0.2 V DD=3.6V 0.1 20 50 100 200 500 Hz 1k 2k 5k 10k 20k V DD=5V 0.1 0.08 20 50 100 200 500 Hz 1k 2k 5k 10k 20k Power Analog Microelectronics , Inc www.poweranalog.com 5 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Typical Operating Characteristics (T =25°C) A 7. Frequency Response +5 +4 +3 +2 +1 +0 -1 -2 -3 -4 -5 20 d B +0 8.PSRR VS Frequency -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 20 Gain=0dB@1kHz Cin=0.47 μ F, R L=8 Ω V DD=3.6V/5V Inputs ac-ground V DD=5V,100mVpp, Cin=0.47 μ F,R L=8 Ω d B r A 50 100 200 500 Hz 1k 2k 5k 10k 20k 30k 50 100 200 500 Hz 1k 2k 5k 10k 9. Crosstalk VS Frequency -50 -55 -60 -65 -70 -75 -80 d B -85 -90 -95 -100 -105 -110 -115 -120 20 50 100 200 d B r A TTTTTT TTT +0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 10. Noise Floor FFT Inputs ac-ground, V DD=5.0V Cin=0.47 μ F, R L=8 Ω Gv=20dB ,R L=4 V DD=5.0V, Po=0.5W R to L L to R 500 Hz 1k 2k 5k 10k 20k -130 -140 -150 20 50 100 200 500 Hz 1k 2k 5k 10k 20k 18 16 14 12 10 8 6 4 2 0 11. Quiescent Current VS Supply Voltage Shutdown Current(uA) No input RL=No Load 0.3 0.25 0.2 0.15 0.1 0.05 0 12. Shutdown Current VS Supply Voltage No input No Load Quiescent Current(mA) 2.5 3 3.5 4 4.5 5 5.5 2.5 3 3.5 4 4.5 5 5.5 Power Supply Voltage(V) Power Supply Voltage(V) Power Analog Microelectronics , Inc www.poweranalog.com 6 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Typical Operating Characteristics (T =25°C) A 2.5 13. Output Power VS Supply Voltage R L=8 Ω 4 3.5 14. Output Power VS Supply Voltage R L=4 Ω Output Power(W) Output Power(W) 2 1.5 1 THD=10% 3 2.5 2 1.5 1 0.5 0 THD=10% THD=1% 0.5 0 2.5 3 3.5 4 4.5 5 Power Supply Voltage(V) 5.5 THD=1% 2.5 3 3.5 4 4.5 5 5.5 Power Supply Voltage(V) 260 15. Rdson VS Output Current PMOSFET Vgs=-5V Drain-source Resistance(Ω) 172 170 168 166 164 162 160 158 156 154 16. Rdson VS Output Current NMOSFET Vgs=5V Drain-source Resistance(Ω) 255 250 245 240 235 230 225 220 215 50 100 200 300 400 500 750 1000 1500 50 100 200 300 400 500 750 1000 1500 Drain-source Current(mA) Drain-source Current(mA) 300 290 280 270 260 250 240 230 220 210 200 17. Frequency VS Supply Voltage Input AC-ground 40 20 18. Gain Control VS Volume Voltage V DD=5V 0 Frequency(KHz) Gain(dB) -20 -40 -60 -80 3 3.5 4 4.5 5 5.5 0.1 0.2 0.4 0.5 0.7 0.8 0.9 1.1 1.2 1.4 1.5 1.6 1.8 1.9 2.1 2.2 2.3 2.5 2.6 2.8 2.9 3.0 3.2 3.3 3.5 3.6 3.7 3.9 4.0 4.2 4.3 4.4 Volume Voltage(V) Power Supply Voltage(V) Power Analog Microelectronics , Inc www.poweranalog.com 7 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Table 1. DC Volume Control S TEP 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Gain (dB) -75 -40 -34 -28 -22 -16 -10 -7.5 -5 -2.5 0 1.5 3 4 4.4 4.8 5.2 5.6 6 6.4 6.8 7.2 7.6 8 8.4 8.8 9.2 9.6 10 10.4 10.8 11.2 STEP 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 Gain (dB) 11.6 12 12.4 12.8 13.2 13.6 14 14.4 14.8 15.2 15.6 16 16.4 16.8 17.2 17.6 18 18.4 18.8 19.2 19.6 20 20.4 20.8 21.2 21.6 22 22.4 22.8 23.2 23.6 24 Power Analog Microelectronics , Inc www.poweranalog.com 8 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Application Notice 1. When the PAM8603M works with LC filters, it should be connected with the speaker before it is powered on, otherwise it will be damaged easily. 2. When the PAM8603M works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker to suppress the possible electromagnetic interference. 3. The input signal should not be too high. If too high, it will cause the clipping of output signal when increasing the volume. Because the DC volume control of the PAM8603M has big gain, it will make the device damaged. 4. When testing the PAM8603M without LC filters by using resistor instead of speaker as the output load, the test results, e.g. efficiency, will be worse than those using speaker as load. Test Setup for Performance Testing PAM8603M Demo Board Load +OUT AP System Input Generator GND - OUT V DD AP LPF AUX-0025 AP System Analyzer Power Supply N otes 1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement done by AP analyzer. 2. Two 22 μ H inductors are used in series with load resistor to emulate the small speaker for efficiency measurement. Power Analog Microelectronics , Inc www.poweranalog.com 9 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control Application Information Mute Operation The MUTE pin is an input for controlling the output state of the PAM8603M. A logic low on this pin disables the outputs, and a logic high 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 . For better power-off pop performance, the amplifier should be placed in the mute mode prior to removing the power supply. Shutdown Operation In order to reduce power consumption while not in use, the PAM8603M contains shutdown circuitry to turn off the amplifier's bias circuitry. The amplifier is turned off when logic low is placed on the SHDN pin. By switching the SHDN pin connected to GND, the PAM8603M 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 PAM8603M 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 that target different noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series resistance (ESR) ceramic capacitor, typically 1.0 μ F, placed as close as possible to the device VDD terminal works best. For filtering lower-frequency noise signals, a large capacitor of 10μF (ceramic) or greater placed near the audio power amplifier is recommended. 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 equation below, 1 2πRiCi 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. fC= 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 produced by the power supply coupling in 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) of 0.47μF to 1.0μF 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. Under Voltage Lock-out (UVLO) The PAM8603M incorporates circuitry to detect low supply voltage. When the supply voltage drops to 1.8V or below, the PAM8603M outputs are disable. The device resumes to normal functional once V DD ≥2.0V. Short Circuit Protection (SCP) The PAM8603M has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output or output-to-GND short. When a short circuit is detected on the outputs, the outputs are disable immediately. If the short was removed, the device activates again. Power Analog Microelectronics , Inc www.poweranalog.com 10 10/2008 Rev 1.0 PAM8603M 3W Filterless Stereo Class-D Audio Amplifier with DC Volume Control O ver Temperature Protection Thermal protection on the PAM8603M prevents the device from damage when the internal die temperature exceeds 135°C. 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. The device begins normal operation at this point without external system interaction. How to Reduce EMI (Electro Magnetic Interference) A simple solution is to put an additional capacitor 1000 μ F at power supply terminal for power line coupling if the traces from amplifier to speakers are short (