PAM8006 10W Stereo Class-D Audio Power Amplifier Key Features General Description The PAM8006 is a 10W (per channel) stereo class-D audio amplifier with fixed gain which offers low THD+N, low EMI, and good PSRR thus high-quality sound reproduction. n 10W@10%THD / Channel Output into a 8Ω Load at 13V n Power Supply Range: 7.5V to 18V n Low SNR: 95dB n Over 90% Efficiency n With Shutdown/Mute Function n Over Current , Thermal, Short-Circuit Protection and UVLO n Low THD+N n Low Quiescent Current n Pop noise suppression n Small Package Outlines: Thin 32-pin QFN 5mm*5mm and TSSOP-28PP Package n RoHS Pass and Green Package The PAM8006 runs off from a 7.5V to 18V supply at much higher efficiency than competitors’ICs. The PAM8006 only requires very few external components, significantly saving cost and board space. The PAM8006 is available in a 32pin QFN 5mm*5mm and TSSOP-28PP package. Applications n n n n n Flat Monitor /LCD TVs Multi-media Speaker System DVD players, Game machines Boom Box Music instruments Typical Application 1μF 1μF 1μF 10 μF 1μF 10 μF 1μF RINN RINP GND 1μF 1μF 1 μF RINN VCLAMP RINP SD GND SHUTDOWN 1μF V2P5 MUTE MUTE SHUTDOWN AGND AVDD PAM8006 MUTE AVCC GND GND 10μF VCC 100nF COSC LINP LINN 1 μF 1μF 220pF LINP GND LINN 1 μF 1μF 10 μF 1μF 1 μF 10 μF Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 1 PAM8006 10W Stereo Class-D Audio Power Amplifier Block Diagram BSRN PVCCR Driver 100k 10k RINN RINP _ - 10k PGNDR PAM Modulation + _ + + - ROUTN BSRP PVCCR + Driver 100k ROUTP PGNDR Feedback System (x5) osc COSC AVCC AGND VCLAMP VCLAMP LDO AVDD UVLO SD on/off Depop Thermal Short Circuit Protection Biases & References LDO V2P5 BSLN MUTE PVCCL Driver 100k 10k LINN LINP _ - 10k + + - PGNDL BSLP PVCCL PAM Modulation + _ + Driver 100k LOUTN LOUTP PGNDL Feedback System (x5) Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 2 PAM8006 10W Stereo Class-D Audio Power Amplifier Pin Configuration & Marking Information Top View 5mm*5mm QFN 32 31 30 29 28 27 26 25 NC 1 24 NC RINN 2 23 SD RINP 3 22 AVCC MUTE 4 21 VCLAMP AVDD 5 20 AGND LINP 6 19 V2P5 LINN 7 18 COSC NC 8 17 NC PAM8006 XATYWWLL 9 10 11 12 13 14 15 16 Top View TSSOP-28PP (Exposed Pad) 1 28 BSRP 2 27 ROUTP PVCCR PGNDR RINN RINP 3 4 26 PVCCR 25 PGNDR 5 24 SD 6 23 AVCC MUTE AVDD LINP 7 8 22 VCLAMP 21 AGND 20 V2P5 19 COSC BSRN ROUTN 9 LINN 10 PGNDL 11 PVCCL 12 LOUTN 13 BSLN 14 X: Internal Code A: Assembly Code T: Testing Code Y: Year WW: Week LL: Internal Code 18 PGNDL 17 PVCCL 16 LOUTP 15 BSLP Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 3 PAM8006 10W Stereo Class-D Audio Power Amplifier Pin Descriptions QFN5X5 TS SOP-28 Name Function 2 5 RINN Negative differential audio in put for right chann el 3 6 RINP Po sitive differential audio input for ri ght cha nnel 1,8 ,17,24 - NC No Conne cted 5 8 AVD D 5V A nalog V DD 4 7 MUTE A logic high on this pin disab les the outputs and a logic low ena bles the outpu ts. 6 9 LINP Po sitive differential audio input for left ch annel 7 10 LINN Negative differential audio in put for left channel 9,16 11 ,18 PGNDL Po wer ground for left channel H- bridge 1 0,15 12,17 PV CCL Po wer sup ply for left channe l H-bridge, not connected to PVCCR o r AVCC. 11 13 LOUTN Class-D 1/2-H-br idg e negative output for left cha nnel 12 14 BSLN Bo otstra p I/O for left cha nnel, n egative h igh-side FET 13 15 BSLP Bo otstra p I/O for left cha nnel, p ositive high-sid e FET 14 16 L OUTP Class-D 1/2-H-br idg e posi tive output for left channel 18 19 COSC 22 23 AVC C 19 20 V 2P5 20 21 A GND 23 24 SD I/O for char ge/d isch arging currents onto capacitor for ramp generator triangle wave biased at V 2P5 High-voltage analog power sup ply (7.5V to 18V) 2.5V Re fere nce for ana log cells, as well as reference for unused au dio in put when usin g singl e-e nded inputs. An alog GND Sh utdown signal for IC (low= shutdown, hi gh =oper ational). TTL logic levels with compliance to VCC. 21 22 VCLA MP Internally generated voltage supply b ootstrap capacitors. 2 5,32 4 ,25 P GNDR Po wer ground for rig ht cha nnel H-br idge 2 6,31 3 ,26 PVCCR Po wer sup ply for r ig ht channel H-b ridge, not connected to PVCCL or AVCC. 27 27 ROUTP Class-D 1/2-H-br idg e posi tive output for right cha nnel 28 28 BSRP Bo otstra p I/O for right channel, positive h ig h-side FET 29 1 BSRN Bo otstra p I/O for right channel, negative high-sid e FE T 30 2 ROUTN Class-D 1/2-H-br idg e negative output for right channel Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 4 PAM8006 10W Stereo Class-D Audio Power Amplifier 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 V CC.............................-0.3V to 20V Input Pin Voltage Range V I: MUTE.................................................0V to 6.0V SD ....................................................-0.3V to V CC RINN,RINP,LINN,LINP......................-0.3V to 6.0V Junction Temperature Range,TJ ......-40°C to 150 °C Storage Temperature.....................-65 °C to150 °C Lead Temperature1,6mm(1/16 inch) from case for 5 seconds.................................................260 °C Recommended Operating Conditions Supply Voltage (VCC )...........................7.5V to 18V Maximum Volume Control Pins, Input Pins Voltage................................................0V to 5.0V High Level Input Voltage: SD .................2.0V to VCC MUTE, ........ ...2.0V to 5V Low Level Input Voltage: SD ...................0 to 0.3V MUTE...............0 to 0.3V Ambient Operating Temperature......-20 °C to 85 °C Junction Temperature Range,TJ ......-40°C to 125°C Thermal Information Param eter Package Symbol Maximum Thermal Resistance QFN 5mm* 5mm θJ C 7.6 (J unction to Case) TSSOP-28PP θJ C 14.4 Thermal Resistance QFN 5mm* 5mm θJA 18.1 (Junction to Ambient) TSSOP-28PP θJA 27.8 Internal Power Dissipation QFN 5mm* 5mm PD 5.52 (T A=25°C) TSSOP-28PP PD 3.60 Unit °C/W W The Exposed PAD must be soldered to a thermal land on the PCB. Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 5 PAM8006 10W Stereo Class-D Audio Power Amplifier Electrical Characteristic T A=25 °C, V CC=12V,Gv=24dB,R L=8 Ω (unless otherwise noted) Par ameter Supply Voltage Continuous Output Power Symbol condition V CC Po Quiescent Current Supply Quiescent Current in shutdown mode Drain-source on-state resistance Power Supply Ripple Rejection Ratio THD+N ICC ISD r ds (on) PSRR MAX Units 7.5 12 18 V 5 THD+ N=1.0%,f=1kHz,RL =8Ω 8 THD+ N=10%,f=1kHz,RL =8Ω, THD+N=10%,f=1kHz,RL =4Ω ( No t e ) Noise TY P THD+ N=0.1%,f=1kHz,RL =8Ω V CC = 13 V Total Harmonic Distortion plus MIN W 10 15 P O=5W, f=1kHz, RL =8Ω 0.1 (no load) 20 30 mA SHUTDOWN=0V 4 10 µA V CC =12V High side 300 IO=1A Low side 300 TA =25℃ Total 600 1V PP ripple, f=1kHz, Inputs ac -coupled to ground % mΩ -60 dB Oscillator Frequency fOSC C O S C = 22 0 p F 250 k Hz Output Integrated Noise Floor Vn 20Hz to 22 kHz, A-weighting -90 dB Crosstalk CS P O=3W, R L =8Ω , f=1kHz -80 dB 95 dB Signal to Noise Ratio Output offset voltage SNR Maximum output at THD+N< 0.5%, f=1k Hz |V OS| INN and INP connected together 30 mV 2.5V Bias voltage V2P5 No Load 2.5 V Internal Analog supply Voltage AVDD V CC =7.5V to 18V Over Temperature Shutdown OTS 150 °C Thermal Hysteresis OTH 40 °C (measured differentially) 5 5.5 V Note: Heat sink is required for high power output. Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 6 PAM8006 10W Stereo Class-D Audio Power Amplifier Typical Performance Characteristics V CC =12V,RL =8 Ω, Gv=24dB,ΤΑ =25 °C, unless otherwise noted. 1. THD +N vs. Power 2. THD+N vs Frequency 50 10 20 5 10 2 5 % % 2 f=1kHz 1 1 Vin=15V f=10kHz 0. 5 Vin=12V 0. 5 f=100Hz 0. 2 0. 2 Vin=8V 0. 1 1m 2m 5m 10 m 20 m 50m 100 m 500m 1 2 5 10 0. 1 20 20 50 100 200 W 50 0 1k 2k 5k 10k 20k 1k 2k 5k 10k 20k 2k 5k 10 k 20 k Hz 3. Power Supply Ripple Rejection 4. Noise Floor +0 +0 -10 -10 -20 -30 -20 -40 -30 -50 -40 d B -60 d B V -50 -60 -70 -80 -90 -100 -70 -110 -80 -120 -130 -90 -140 -100 10 20 50 100 200 500 1k 2k 5k 10k 20k -150 20 50k 100k 50 100 200 500 Hz Hz 5. Crosstalk 6. Frequency Response + 30 +0 + 29 -10 + 28 + 27 -20 + 26 -30 + 24 -40 d B Cin=1uF + 25 d B r -50 + 23 + 22 L to R -60 Cin=0.47uF A + 21 + 20 -70 + 19 + 18 -80 R to L Cin=0.1uF + 17 -90 + 16 - 100 20 50 100 200 500 1k 2k 5k 10 k + 15 20 20 k Hz 50 100 200 500 1k Hz Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 7 PAM8006 10W Stereo Class-D Audio Power Amplifier Typical Performance Characteristics V CC =12V,RL =8 Ω, Gv=24dB,ΤΑ =25 °C, unless otherwise noted. 7. Efficiency vs Power 8. Quesicent Current vs Supply Voltage 100 25 90 24 80 23 70 22 60 21 50 20 40 19 30 18 20 17 10 16 0 15 0 2 4 6 8 6 10 8 10 12 14 16 18 20 Supply Voltage(V) Output Power(mW) Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 8 PAM8006 10W Stereo Class-D Audio Power Amplifier Test Setup for Performance Testing PAM8006 Demo Board Load Audio Precision (AP) System Generator AP +OUT Input Low Pass AP System Analyzer Filter GND -OUT 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. Application Information Power and Heat Dissipation If the rated workable junction temperature is 1 5 0 °C , t h e r e l a t i o n s h i p b e t w e e n a m b i e n t temperature and permitted P loss is shown in below diagram. Choose speakers that are able to stand large output power from the PAM8006. Otherwise, speaker may suffer damage. Heat dissipation is very important when the device works in full power operation. Two factors affect the heat dissipation, the efficiency of the device that determines the dissipation power, and the thermal resistance of the package that determines the heat dissipation capability. 10 In operation, some of power is dissipated to the resistors. 4 9 8 7 6 5 3 2 Power Dissipation: P loss =(Po*(1- η)/ η)*2 1 0 The PAM8006’s efficiency is 90% with 10W ouput and 8 Ω load. The dissipation power is 2.22W. 0 20 40 60 80 100 Ta Thermal resistance of junction to ambient of the QFN package is 18.1°C/W and the junction temperature Tj=Ploss * θjA+Ta, where Ta is ambient temperature. If the ambient temperature is 85°C, the QFN’s junction temperature From the diagram, it can be found that when the device works at 10W/8Ω load the dissipation power is 1.1W per channel, 2.2W total, the permitted ambient temperature is over 100°C. This is proven by actual test. The PAM8006 can work in full output power under 85°C ambient temperature. Tj=2.22*18.1+85=125°C w hi c h is l o we r th a n 1 5 0°C r a t ed j un c ti o n temperature. Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 9 PAM8006 10W Stereo Class-D Audio Power Amplifier Heat Dissipation in PCB design Consideration for EMI Generally, class-D amplifiers are high efficiency and need no heat sink. For high power ones that has high dissipation power, the heat sink may also not necessary if the PCB is carefully designed to achieve good heat dissipation by the PCB itself. Filters are not required if the traces from the amplifier to the speakers are short (<20cm). But most applications require a ferrite bead filter as shown in below figure. The ferrite bead filter reduces EMI of around 1MHz and higher to meet the FCC and CE's requirements. It is recommended to use a ferrite bead with very low impedances at low frequencies and high impedance at high frequencies (above 1MHz). Dual-Side PCB To achieve good heat dissipation , the PCB’s copper plate should be thicker than 0.035mm and the copper plate on both sides of the PCB should be utilized for heat sink. Ferrite Bead OUTP The thermal pad on the bottom of the device should be soldered to the plate of the PCB, and via holes, usually 9 to 16, should be drilled in the PCB area under the device and deposited copper on the vias should be thick enough so that the heat can be dissipated to the other side of the plate. There should be no insulation mask on the other side of the copper plate. It is better to drill more vias on the PCB around the device if possible. OUT+ 200pF Ferrite Bead OUTN OUT200pF The EMI characteristics are as follows after employing the ferrite bead. Vertical Polarization 4-layer PCB If it is 4-layer PCB, the two middle layers of grounding and power can be employed for heat dissipation, isolating them into serval islands to avoid short between ground and power. Horizontal Polarization Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 10 PAM8006 10W Stereo Class-D Audio Power Amplifier MUTE Operation Power Supply Decoupling, C S The MUTE pin is an input for controlling the output state of the PAM8006. A logic high on this pin disables the outputs and low enables the outputs. This pin may be used as a quick disable or enable of the outputs. The PAM8006 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total harmonic distortion (THD) as low as possible. Power supply decoupling also prevents oscillations caused by long lead between the amplifier and the speaker. The optimum decoupling is achieved by using two capacitors of different types that target 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 1µF, is recommended, placing as close as possible to the device’s VCC lead. To filter lowerfrequency noises, a large aluminum electrolytic capacitor of 10µF or greater is recommended, placing near the audio power amplifier. The 10µF capacitor also serves as a local storage capacitor for supplying current during large signal transients on the amplifier outputs. For power saving, the SD pin should be used to reduce the quiescent current to the absolute minimum level. Shutdown Operation The PAM8006 employs a shutdown operation mode to reduce supply current to the absolute minimum level during periods of non-use to save power. The SD input terminal should be held high during normal operation when the amplifier is in use. Pulling SD low causes the outputs to mute and the amplifier to enter a low-current state. SD should never be left unconnected to prevent the amplifier from unpredictable operation. BSN and BSP Capacitors For the best power-off pop performance, the amplifier should be set in shutdown mode prior to removing the power supply voltage. The full H-bridge output stages use NMOS tra nsistors only. They therefore require bootstrap capacitors for the high side of each output to turn on correctly. A at least 220nF ceramic capacitor, rated for at least 25V, must be connected from each output to its corresponding bootstrap input. Specifically, one 220nF capacitor mus t be connected from xOUTP to xBSP, and another 220nF capacitor from xOUTN to xBSN. It is recommended to use 1 μF BST capacitor to replace 220nF (pin15, pin16, pin35 and pin36) for lower than 100Hz applications. Internal 2.5V Bias Generator Capacitor Selection The internal 2.5V bias generator (V2P5) provides the internal bias for the preamplifier stage. The exter nal input capa citor s and this inter nal reference allow the inputs to be biased within the o p t i m a l c o m m o n - m o d e r a n g e o f th e i n p u t preamplifiers. The selection of the capacitor value on the V2P5 terminal is critical for achieving the best device performance. During startup or recovery from shutdown state, the V2P5 capacitor determines the rate at which the amplifier starts up. When the voltage on the V2P5 capacitor equals 0.75 x V2P5, or 75% of its final value, the device turns on and the class-D outputs start switching. The startup time is not critical for the best de-pop performance since any heard pop sound is the result of the class-D output switching-on other than that of the startup time. However, at least a 0.47µF capacitor is recommended for the V2P5 capacitor. Another function of the V2P5 capacitor is to filter high frequency noise on the internal 2.5V bias generator. VCLAMP Capacitors To ensure that the maximum gate-to-source voltage for the NMOS output transistors not exceeded, two internal regulators are used to clamp the gate voltage. Two 1µF capacitors must be connected from VCLAMP to ground and must be rated for at least 25V. The voltages at the VCLAMP terminals vary with V CC and may not be used to power any other circuitry. Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 11 PAM8006 10W Stereo Class-D Audio Power Amplifier R is the internal resistor and the vaule is 400kΩ and with ± 20 % tolerance.The frequency may varies from 200kHz to 300kHz by adjusting the values of C OSC . The recommended value is COSC = 220pF for a switching frequency of 250kHz. Internal Regulated 5-V Supply (AVDD) The AVDD terminal is the output of an internallygenerated 5V supply, used for the oscillator, preamplifier. It requires a 0.1µF to 1µF capacitor, placed very close to the pin to Ground to keep the regulator stable. The regulator may not be used to power any external circuitry. Selection of Gain and Input Signal Amplitude The PAM8006 has two internal amplifier stages with fixed gain. The pre-amp stage gain is 10X, while the second stage gain is 5X. The pre-amp is powered internally by the 5V value of AVDD. At maximum pre-amp gain operation for avoiding the pre-amp saturation, it's worth noting that the peak value of input signal (Vp) shouldn't exceed 250mV when the THD+N of PAM8006 is lower than 1%; and the Vp value shouldn't exceed 300mV when the THD+N is lower than 10%. Total gain is calculated as follows: Gain=20log[100k/(10k+R IN )*5] (RIN is external input resistor.) Differential Input The differential input stage of the amplifier eliminates noises that appear on the two input lines of the channel. To use the PAM8006 with a differential source, connect the positive lead of the audio source to the INP input and the negative lead from the audio source to the INN input. To use the PAM8006 with a single-ended source, acground the INP input through a capacitor equal in value to the input capacitor on INN and apply the audio source to the INN input. In a single-ended input application, the INP input should be acgrounded at the audio source other than at the device input for best noise performance. Thermal Protection Thermal protection on the PAM8006 prevents damage to the device when the internal die temperature exceeds 150°C. There is a ±15 degree tolerance on this trip point from device to device. Once the die temperature exceeds the set thermal point, the device enters into the shutdown state and the outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 40°C. The device begins normal operation at this point without external system intervention. Using low-ESR Capacitors Low-ESR capacitors are recommended throughout this application section. A real (with respect to ideal) capacitor can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this resistance the more the real capacitor behaves as an ideal capacitor. Short-circuit Protection The PAM8006 has short circuit protection circuitry on the outputs to prevent damage to the device when output-to-output shorts, output-to-GND shorts, or output-to-VCC shorts occur. Once a short-circuit is detected on the outputs, the output drive is immediately disabled. This is a latched fault and must be reset by cycling the voltage on the SD pin to a logic low and back to the logic high state for normal operation. This will clear the short-circuit flag and allow for normal operation if the short was removed. If the short was not removed, the protection circuitry will again activate. Selection of COSC and Frequency Setting The switching frequency is determined by the values of components connected to COSC and calculated as follows: f OSC = 22 / (Cosc*R) Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 12 PAM8006 10W Stereo Class-D Audio Power Amplifierl Ordering Information PAM8006 X X Shipping Package Package Type Part Number PAM8006TR PAM8006HR Marking PAM8006 XATYWWLL PAM8006 XATYWWLL Package Type Standard Package QFN 5mm*5mm 3,000 units/Tape & Reel TSSOP-28PP 2,500 units/Tape & Reel Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 13 PAM8006 10W Stereo Class-D Audio Power Amplifier Outline Dimension 32pin QFN Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 14 PAM8006 10W Stereo Class-D Audio Power Amplifier Outline Dimension TSSOP-28PP Power Analog Microelectronics, Inc www.poweranalog.com 03/2011 Rev1.0 15