PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Key Features General Description 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 n Headphone Output Function n Superior Low Noise n Low pop noise n Efficiency up to 92% n Short Circuit Protection n Thermal Shutdown n Few External Components to Save the Space and Cost n Pb-Free Package The PAM8007 is a 3W, class-D audio amplifier with headphone amplifier. Advanced 64-step DC volume control minimizes external components and allows speaker volume control and headphone volume control. It offers low THD+N, to produce high-quality sound reproduction. The new filterless architecture allows the device to drive the speaker directly, without low-pass output filters , which will save 30% system cost and 75% PCB area. With the same numbers of external components, the efficiency of the PAM8007 is muc h better than class-AB cousins. It can extend the battery life thus be ideal for portable ap plications. The PAM8007 is available in a SSOP-24 and SOP24 package. Applications n n n n n LCD Monitors / TV Projectors Notebook Computers Portable Speakers Portable DVD Players, Game Machines VoIP/Speaker Phones Typical Application PVDDL 10 μF 1 μF 5 0.47 μF INL 0.47 μF 8 9 0.47 μF 17 INR 0.47 μF ON 16 19 SHDN ON 2 PVDDL PGNDL INL 3 PGNDL +OUTL EarInL -OUTL - INR +OUTR EarInR 4 1 21 24 -OUTR - PAM8007 SHDN 6 MUTE MUTE 13 220μF 220μF + EarOutR 11 DC Volume 7 VDD 1 μF 10 + V OLUME 12 VDD - Headphone EarOutL VDC 15 1 μF 14 Line/Ear VREF PVDDR 20 PGNDR PGNDR 22 23 1 μF GND 18 H: Headphone L: Class D (de fault) 10μF Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 1 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Block Diagram VDD PVDD PGND Headphone EarInR EarOutR VDD/2 + + - - INR +OUT_R DRIVER -OUT_R MODULATOR Thermal Protection VDC MUTE INTERNAL OSCILLATOR SHDN BIAS AND REFERENCES VREF LINE/EAR VOLUME OSC Current Protection +OUT_L MODULATOR DRIVER - INL - + -OUT_L + VDD/2 Headphone EarInL EarOutL GND PVDD PGND Pin Configuration & Marking Information SOP24 Top View SSOP24 Top View -OUT_L 1 24 -OUT_R PGNDL PGNDL +OUT_L PVDDL 2 3 23 22 4 21 20 5 MUTE 6 VDD 7 INL 8 EarInL 9 VDC 10 VOLUME 11 EarOutL 12 19 18 17 16 15 14 13 -OUT_L PGNDR PGNDR +OUT_R PVDDR SHDN GND INR EarInR LINE/EAR VREF EarOutR 1 PGNDL 2 PGNDL 3 +OUT_L 4 PVDDL 5 MUTE 6 VDD 7 INL 8 EarInL 9 VDC 10 VOLUME 11 EarOutL 12 24 -OUT_R 23 22 21 20 19 18 17 16 15 14 13 PGNDR PGNDR +OUT_R PVDDR SHDN GND INR EarInR LINE/EAR VREF EarOutR X: Internal Code Y: Year WW: Week LL: Internal Code Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 2 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Pin Descriptions Pin Number Pin Name Desc ription 1 - OUT_L Left Channel Nega tive Ou tput 2 PGNDL Left Channel Power GND 3 PGNDL Left Channel Power GND 4 +OUT_L Left Channel Posi tive Ou tput 5 PVDDL Left Channel Power Sup ply 6 MUTE Mute Contr ol Input(active low) 7 VDD 8 INL Left Channel Inpu t 9 Ear InL Left Earpho ne inp ut 10 VDC 11 V OLUME 12 EarOutL Left Earpho ne output(Non -Inverting) 13 EarOutR Right Earph one ou tput(Non-In verting) 14 VREF 15 LINE/EAR 16 EarInR Right Earph one in put 17 INR Right Channel Inp ut 18 GND Anal og GND 19 SHDN 20 PVDDR Right Channel Power Sup ply 21 +OUT_R Right Channel Positive Output 22 PGNDR Right Channel Power GND 23 PGNDR Right Channel Power GND 24 -OUT_R Right Channel Ne gative Output Anal og VDD Anal og reference for gain control sectio n DC volume control to set the ga in of Class-D Inter nal ana log reference, connect a b ypass capacitor fr om VREF to GND Line / earph one S witch.sp eaker output(active low),Ea rphone outpu t(active high) Shutdown Control Input(active l ow) 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 ............................................6.0V Storage Temperature.....................-65°C to 150 °C Input Voltage.............................-0.3V to V DD+0.3V Soldering Temperature....................... 300°C,5sec Maximun Junction Temperature...................150°C Recommended Operating Conditions Supply Voltage Range....................... 2.5V to 5.5V Junction Temperature Rang...........-20 °C to 125 °C Ambient Operation Temperature Range............................................-20 °C to 85 °C Thermal Information Parameter Symbol Package Maximum Unit Thermal Re sistance (Junction to Ambient) θJA SSOP-2 4 96 °C/W Thermal Re sistance (Junction to Ambient) θJA SOP-24 79.2 °C/W Thermal Re sistance (Junction to Ambient) θJC SSOP-2 4 32 °C/W Thermal Re sistance (Junction to Ambient) θJC SOP-24 27 °C/W Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 3 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Electrical Characteristic V DD =5V, Gain = 24dB, R L =8 Ω, T A =25°C, unless otherwise noted. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V Class D Stage Supply Voltage Range Quiescent Current Output Offset Voltage Drain-Source On-State Resistance Output Power VDD 2.5 IQ No Load 12 16 mA VOS No Load 10 50 mV RDS(ON) IDS =0.5A PO P MOSFET 0.23 N MOSFET 0.17 RL= 8Ω RL= 4Ω THD+N=10%, f=1kHz 1.55 1.75 2.85 3.1 Ω W Total Harmonic Distortion Plus Noise THD+ N RL=8Ω, PO=1W,f=1KHz RL=4Ω, PO=2W,f=1KHz Power Supply Ripple Rejection Input AC-GND, f=1KHz, Vpp=200mV 63 dB Vo=1Vrms, f=1KHz -88 dB PSRR Channel Separation CS Oscillator Frequency fOSC Efficiency η Noise Vn Signal Noise Ratio SNR 0.12 % 0.15 200 250 PO=1.75W,f=1kHz, RL=8Ω 85 92 % PO=3.0W,f=1kHz, RL=4Ω 80 88 % Input AC-GND Gain=12dB A-weighting 65 No A-weighting 90 300 kHz uV f=20-20kHz, THD=1% 84 dB THD+N=1%, RL=32Ω, f=1kHz 69 mW 0.04 % Earphone Stage Output Power PO Total Harmonic Distortion Plus Noise THD+ N RL=32Ω, PO =10mW, f=1kHz Power Supply Ripple Rejection Input AC-GND, f=1kHz, Vpp=2 00mV 73 dB Vo=1Vrms, f=1kHz 95 dB Input A-weig hting 19 AC-GND No A-weighting 25 PSRR Channel Separation CS Noise Vn Signal Noise Ratio SNR f=20-20kHz, THD=1% 97 Mute Current IMUTE VMUT E= 0V 8 Shutdown Current ISHDN VSHDN= 0V SHDN Input High VSH SHDN Input Low VSL MUTE Input High VMH MUTE Input Low VML Line/Ear Input High VDH Line/Ear Input Low VDL uV dB Control Section 12 mA 20 µA 1.5 0.4 1.5 0.4 2.5 0.4 V V V Over Temperature Protection OTP 150 °C Over Temperature Hysteresis OTH 30 °C Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 4 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (T =25°C) A Speaker 1. THD+N vs Output Power 2. THD+N vs Output Power 30 30 20 10 20 RL=4 Ω VDD=5V 10 5 5 2 % 2 % 1 1 0.5 0.5 0.2 0.2 0.1 1m RL=8 Ω VDD=5V 2m 5m 10m 20m 50m 100m 200m 500m 1 2 0.1 1m 4 2m 5m 10m 20m 50m W 3. THD+N vs Frequency 200m 500m 1 2 4 4. THD+N vs Frequency 10 5 100m W 10 VDD=5V RL=4Ω Po=0.3W/1W/2W VDD=5V RL=8Ω Po=0.3W/1W/1.3W 5 2 2 Po=0.3W 1 Po=0.3W 1 0.5 0.5 % % 0.2 0.2 0.1 0.1 Po=1W 0.05 Po=1.3W Po=2W 0.02 0.01 20 Po=1W 0.05 0.02 50 100 200 500 1k 2k 5k 10k 0.01 20 20k 50 100 200 500 Hz 1k 2k 5k 10k 20k Hz 5. PSRR vs Frequency 6. Crosstalk vs Frequency +0 +0 TTTTTTTTTTTTT T TTTTTT TT T -5 T -10 -10 -20 -15 -20 -30 -25 -40 -30 d B d B -35 -40 -50 -60 L to R -45 -70 -50 -55 -80 -60 -90 -65 -70 20 50 100 200 500 1k 2k 5k 10k -100 20 20k R to L 50 100 200 500 1k 2k 5k 10k 20k Hz Hz Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 5 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (T =25°C) A Speaker 7. Frequency Response 8. Noise Floor +30 -50 -55 +28 +26 -60 Cin=2.2uF -65 -70 +24 -75 +22 d B g +20 A +18 Cin=0.1uF Cin=0.47uF Cin=1uF d B g -80 A -90 -85 -95 +16 -100 -105 +14 -110 +12 +10 20 -115 50 100 200 500 1k 2k 5k 10k -120 20 20k 50 100 200 500 1k 2k 5k 10k 20k Hz Hz 9. Power Dissipation vs Output Power 10. Power Dissipation vs Output Power 450 180 RL=4 Ω 400 RL=8Ω 160 350 140 300 120 250 100 200 80 150 60 100 40 50 20 0 0 0 500 1000 1500 2000 2500 3000 3500 0 500 Output Power(mW) 1000 1500 2000 Output Power(mW) 11. Efficiency vs Output Power 12. Efficiency vs Output Power 100 100 90 90 80 80 70 70 60 60 50 50 40 40 30 30 RL=4Ω VDD=5V 20 20 RL=8 Ω VDD=5V 10 10 0 0 0 500 1000 1500 2000 2500 3000 3500 0 O ut put Power (mW) 500 1000 1500 2000 Output Power(mW) Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 6 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (T =25°C) A Speaker 13. Output Power VS Supply Voltage 14. Output Power VS Supply Voltage 4000 2500 3500 RL=4Ω VDD=5V RL=8Ω VDD=5V 2000 3000 2500 1500 2000 1000 1500 1000 500 500 0 0 2 3 4 5 6 2 3 Supply Voltage(V ) 4 5 6 5 6 60 80 Supply Voltage(V) 15. Rdson VS Output Current 16. Quiescent Current 290 16 270 14 12 250 10 230 8 210 6 190 4 170 R-Pmos R-Nmos 2 0 150 0 500 1000 1500 2000 2 3 4 Supply Voltage(V) OutputCurrent(mA) 17. Switching Frequency VS Supply Voltage 18. Gain Step 256 30 254 20 252 10 250 0 248 -10 246 -20 244 242 -30 240 -40 238 -50 2 2.5 3 3.5 4 4.5 5 5.5 6 0 S upply V oltage(V) 20 40 Step Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 7 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (continued) Earphone Output 1. THD+N vs Output Power 2. THD+N vs Output Power 30 30 20 20 RL=16Ω VDD=5V 10 5 5 2 2 1 % 1 0.5 % f=10kHz f=1kHz 0.2 0.5 0.1 0.1 0.05 0.02 5u 10u 20u 50u 100u f=1kHz 0.02 f=100Hz 2u f=10kHz 0.2 0.05 0.01 1u RL=32Ω VDD=5V 10 200u 500u 1m 2m 5m 10m 20m 50m f=100Hz 0.01 1u 100m 2u 5u 10u 20u 50u 100u 200u 500u W 2m 5m 10m 20m 50m 100m W 3. THD+N vs Frequency 4. THD+N vs Frequency 10 5 1m 10 VDD=5V RL=16Ω Po=1mW/10mW/60mW VDD=5V RL=32Ω Po=1mW/10mW/50mW 5 2 2 1 1 0.5 0.5 % % Po=1mW 0.2 Po=50mW 0.2 Po=10mW 0.1 0.1 0.05 0.05 Po=10mW 0.02 Po=10mW 0.02 Po=1mW 0.01 20 50 100 200 500 1k 2k 5k 10k 0.01 20 20k 50 100 200 Hz 1k 2k 5k 10k 20k H z 5. PSRR vs Frequency +0 500 6. Crosstalk vs Frequency +0 T TTT TTTTTT T TTTTT TTTTTTTTT TTT T TTT TTTTTTTT TTTTT TTTTTT TT T TT T TTTTTTTT TTTTTTTTT TT TTT TT T TT TT TT TTTT TTT T TTTT TTT TT T TT T T TT TTTTT TT TTT T TT T TT TT TT T -5 -10 -10 -15 -20 -20 -30 -25 -30 -40 -35 -50 -40 d B d B -45 -50 -55 -60 L to R -70 -60 -80 -65 -70 -90 -75 R to L -1 00 -80 -85 -90 20 50 100 200 500 1k 2k 5k 10k -110 20 20k Hz 50 100 200 500 Hz 1k 2k 5k 10k 20k Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 8 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (T =25°C) A 7. Frequency Response 8. Noise Floor -50 +5 +4 -55 Cin=2.2uF +3 -60 +2 -65 +1 -70 -0 -75 Cin=0.1uF Cin=0.47uF -1 d B g -2 Cin=1uF -3 A d B g -80 A -90 -85 -4 -95 -5 -100 -6 -105 -7 -8 -110 -9 -115 -10 20 50 100 200 500 1k 2k 5k 10k -120 20 20k 50 100 200 500 1k 2k 5k 10k 20k H z Hz 9.Gain Step 10 0 -10 -20 -30 -40 -50 -60 -70 -80 0 10 20 30 40 50 60 70 Step Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 9 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Typical Operating Characteristics (continued) Table 1. DC Volume Control Gain(dB) Gain(dB) Gain(dB) Gain(dB) Class D Earphone Class D Earphone 1 -80 -80 33 11.6 -9.2 2 -40 -60 34 12 -8.6 3 -34 -50 35 12.4 -8 4 -28 -40 36 12.8 -7.4 5 -22 -37.7 37 13.2 -6.8 6 -16 -35.4 38 13.6 -6.2 7 -10 -33.1 39 14 -5.7 8 -7.5 -30.8 40 14.4 -5.2 9 -5 -28.5 41 14.8 -4.7 10 -2.5 -27.5 42 15.2 -4.2 11 0 -26.4 43 15.6 -3.7 12 1.5 -25.3 44 16 -3.2 13 3 -24.2 45 16.4 -2.7 14 4 -23.1 46 16.8 -2.2 15 4.4 -22.2 47 17.2 -1.8 16 4.8 -21.4 48 17.6 -1.4 17 5.2 -20.6 49 18 -1 18 5.6 -19.8 50 18.4 -0.6 19 6 -19 51 18.8 -0.2 20 6.4 -18.2 52 19.2 0.2 21 6.8 -17.4 53 19.6 0.6 22 7.2 -16.6 54 20 0.9 23 7.6 -15.9 55 20.4 1.2 24 8 -15.2 56 20.8 1.5 25 8.4 -14.5 57 21.2 1.8 26 8.8 -13.8 58 21.6 2.1 27 9.2 -13.1 59 22 2.4 28 9.6 -12.4 60 22.4 2.7 29 10 -11.7 61 22.8 2.9 30 10.4 -11 62 23.2 3.1 31 10.8 -10.4 63 23.6 3.3 32 11.2 -9.8 64 24 3.5 STEP STEP Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 10 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Test Setup for Performance Testing(Class D) Application Notice make the device damaged. Therefore, it's recommended to use either 4 Ni-MH (Nickel Metal Hydride) rechargeable batteries or 3 dry or alkaline batteries. 1. When the PAM8007 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 PAM8007 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. 4. 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 PAM8007 has big gain, it will make the device damaged. 3. The absolute maximum rating of the PAM8007 operation voltage is 6.0V. When the PAM8007 is powered with 4 battery cells, it should be noted that the voltage of 4 new dry or alkaline batteries is over 6V, higher than its maximum operation voltage, which probably 5. When testing the PAM8007 without LC filters b y using resistor instead of speaker as the output load, the test results, e.g. THD or efficiency, will be worse than those using speaker as load. PAM8007 Demo Board Load +OUT Audio Precision (AP) System Generator Input AP Low Pass Filter GND -OUT AP System Analyzer AUX-0025 VDD Power Supply Notes 1. The Audio Precision(AP) AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer. 2. Two 22µH inductors are used in series with load resistor to emulate the small speaker for effic iency measurement. Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 11 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Application Information(continued) fC= 1 2πRi Ci Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 12 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Application Information(continued) Over Temperature Protection Thermal protection on the PAM8007 prevents the device from damage when the internal die temperature exceeds 150℃. 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 ℃ . This large hysteresis will prevent motor boating sound well. The device begins normal operation at this point without external system interaction. channel amplifier has two seperate channels and consequently must have two seperate output noise ground traces. The layout of the PAM8007 offers separate PGND connections for each channel and in some cases each side of the bridge. Output noise grounds must be tied to system ground at the power in exclusively. Signal currents for the inputs, reference, etc need to be returned to quite ground. This ground is only tied to the signal components and the GND pin, and GND then tied to system ground. PCB Layout Example How to Reduce EMI (Electro Magnetic Interference) A simple solution is to put an additional capacitor 1000uF 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 at Figure 1. The ferrite filter reduces EMI around 1 MHz and higher. When selecting a ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies (MH2012HM221-T). Fe rrite Bea d OUT+ 22 0p F Figure 2: Top Layer Fe rrite Bea d OUT22 0p F Figure 1: Ferrite Bead Filter to reduce EMI PCB Layout Guidelines Grounding At this stage it is paramount to notice the necessity of separate grounds. Noise currents in the output power stage need to be returned to output noise ground and nowhere else. Were these currents to circulate elsewhere, they may get into the power supply, the signal ground, etc, worse yet, they may form a loop and radiate noise. Any of these cases results in degraded amplifier performance. The logical returns for the output noise currents associated with Class D switching are the respective PGND pins for each channel. The switch state diagram illustrates that PGND is instrumental in nearly every switch state. This is the perfect point to which the output noise ground trace should return. Also note that output noise ground is channel specific. A two Figure 3: Bottom Layer Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 13 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Ordering Information PAM8007 X X X Shipping Package Number of Pins PackageType Part Number Package Type Standard P ackage PAM8007NHR SSOP-24 2,500 Units/Tape & Reel PAM8007DHR SOP-24 1,000 Units/Tape & Reel Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 14 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Outline Dimension SSOP-24 Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 15 PAM8007 Filterless 3W Class-D Stereo Audio Amplifier with DC Volume Control and Headphone Output Outline Dimension SOP-24 Power Analog Microelectronics, Inc www.poweranalog.com 01/2012 Rev1.2 16