IRAUDAMP18 35W/4Ω x 2 Channel Class D Audio Power Amplifier Using the IR4312 By Jun Honda, Liwei Zheng CAUTION: International Rectifier suggests the following guidelines for safe operation and handling of IRAUDAMP18 Demo board; Always wear safety glasses whenever operating Demo Board Avoid physical contact with exposed metal surfaces when operating Demo Board Turn off Demo Board when placing or removing measurement probes www.irf.com IRAUDAMP18 REV 1.0 Page 1 of 13 TABLE OF CONTENTS ........................... PAGE INTRODUCTION..............................................................................3 SPECIFICATIONS ...........................................................................3 CONNECTION SETUP ....................................................................4 TEST PROCEDURES......................................................................5 PERFORMANCE AND TEST GRAPHS ..........................................5 THERMAL INFORMATION..............................................................8 SCHEMATIC ....................................................................................9 IRAUDAMP18 BILL OF MATERIALS ............................................10 IRAUDAMP18 PCB SPECIFICATIONS.........................................11 REVISION CHANGES DESCRIPTIONS .......................................13 www.irf.com IRAUDAMP18 REV 1.0 Page 2 of 13 Introduction The IRAUDAMP18 reference design is a two-channel, 35W/ch half-bridge Class D audio power amplifier with single power supply. This reference design demonstrates how to use the IR4312 IC with single power supply, implement protection circuits, and design an optimum PCB layout using PowIRaudio integrated Class D IC. This reference design does not require additional heatsink or fan cooling for normal operation (one-eighth of continuous rated power).The reference design provides all the required housekeeping power supplies for ease of use. The two-channel design is scalable for power and the number of channels. Applications Docking station audio systems PC audio systems Musical instruments Karaoke amplifiers Game consoles Powered speaker systems Car audio amplifiers Features Output Power: Multiple Protection Features: PWM Modulator: 35W x 2 channels (4Ω load) Over-current protection (OCP), high side and low side Over-voltage protection (OVP), Under-voltage protection (UVP), high side and low side Over-temperature protection (OTP) Self-oscillating half-bridge topology Specifications General Test Conditions (unless otherwise noted) Supply Voltages 18-31V Load Impedance 2-4Ω Self-Oscillating Frequency 400kHz Gain Setting 21.4dB Notes / Conditions Resistive load No input signal, Adjustable 1Vrms input yields rated power Electrical Data Typical Notes / Conditions IR Devices Used IR4312 PowIRaudio integrated Class D IC Modulator Self-oscillating, second order sigma-delta modulation, analog input Single power supply; Power Supply Range 18-31V Output Power CH1-2: (1% THD+N) 26W 1kHz Output Power CH1-2: (10% THD+N) 35W 1kHz Rated Load Impedance 2-4Ω Resistive load Idling Supply Current 70mA No input signal Total Idle Power Consumption 2.2W No input signal Distortion 0.018% THD+N @ 3W, 4Ω Residual Noise IHF-A weighted, AES-17 filter 180V Single-channel driven, 35W, Class D Channel Efficiency 96% stage www.irf.com IRAUDAMP18 REV 1.0 Page 3 of 13 Connection Setup 18-31 3A DC supply 100W, Non-inductive Resistors 4 Ohm 4 Ohm P1 P2 P3 CH1 Output CH2 Output Power Indicator CLIP Indicator IR4312 Audio CN1 Input FAULT Indicator SW1 SW1:PWM Shutdown/MUTE Audio Signal Generator Fig 1 Typical Test Setup Connector Description Audio IN POWER CH1 OUT CH2 OUT www.irf.com CN1 P3 P1 P2 Analog input for CH1 and CH2 Single supply Output for CH1 Output for CH2 IRAUDAMP18 REV 1.0 Page 4 of 13 Test Procedures Test Setup: 1. 2. 3. 4. 5. 6. 7. 8. Connect 4, 100W load to both output connectors, P1 and P2 and audio analyzer (Ap). Connect Audio Signal Generator to CN1 for CH1 and CH2 respectively (Ap). Connect a single power supply to P3 pre-adjusted to 18-31V as shown on Figure above Turn on the power supply. Turn on SW1(right side). Blue LED (Normal) stays turning on after RED LED extinguished. With an Oscilloscope, monitor switching waveform at VS of CH1 and CH2. Quiescent current for the power supply should be 70mA 10mA at 31V. Functionality Audio Tests: 9. Sweep the audio signal voltage from 15 mVRMS to 1.5 VRMS. 10. Monitor the output signals at P1/P2 with an oscilloscope. The waveform must be a non distorted sinusoidal signal with input sinusoidal signal below 1Vrms. Performance and Test Graphs Power vs THD+N Test Conditions: VBus = 31V Input Signal=1 kHz Load Impedance = 4 ohms THD+N vs Power 10 5 2 1 0.5 0.2 % 0.1 0.05 0.02 0.01 0.005 0.002 0.001 20m 50m 100m 200m 500m 1 2 5 10 20 W Sweep Trace Color Line Style Thick Data Axis Comment 1 1 1 3 Red Blue Solid Solid 2 2 Anlr.THD+N Ratio Anlr.THD+N Ratio Left Left Ch1 4ohms 31V Ch2 4ohms 31V Fig 2 www.irf.com IRAUDAMP18 REV 1.0 Page 5 of 13 40 Frequency Response Test Conditions: VBus = 31V Set Output = 1V Load Impedance = 4 ohms +4 +2 +0 d B r -2 -4 A -6 -8 -10 20 50 100 200 500 1k 2k 5k 10k 20k 50k 100k 200k Hz Sweep Trace Color Line Style Thick Data Axis Comment 1 1 1 2 Red Blue Solid Solid 2 2 Anlr.Level A Anlr.Level B Left Left Ch1 4ohm SP 25V Ch2 4ohm SP 25V Fig 3 Noise Floor Test Conditions: VBus = 31V Load Impedance = 4 ohms No Input Signal +20 +0 -20 -40 d B V -60 -80 -100 -120 -140 10 20 50 100 200 500 1k 2k 5k 10k 20k Hz Sweep Trace Color Line Style Thick Data Axis Comment 1 1 1 2 Red Blue Solid Solid 2 2 Fft.Ch.1 Ampl Fft.Ch.2 Ampl Left Left Ch1 Ch2 Fig 4 www.irf.com IRAUDAMP18 REV 1.0 Page 6 of 13 Noise Floor with 1Vrms Output Test Conditions: VBus = 31V Output = 1Vrms @ 1 KHz Load Impedance = 4 ohms +0 -20 -40 d B V -60 -80 -100 10 20 50 100 200 500 1k 2k 5k 10k 20k Hz Sweep Trace Color Line Style Thick Data Axis Comment 1 1 1 2 Red Blue Solid Solid 2 2 Fft.Ch.1 Ampl Fft.Ch.2 Ampl Left Left Ch1 4ohm Ch2 4ohm Fig 5 Efficiency 100.0% 90.0% 80.0% Efficiency 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% 0 5 10 15 20 25 30 35 40 Power (W) Fig 6 www.irf.com IRAUDAMP18 REV 1.0 Page 7 of 13 Thermal Information: 1/8 Po Thermal Test Conditions: Tamb=25°C natural convection cooling Both Channel Driven 1/8Po continuous 30mins Temperature measured by infrared camera Fig 7 IRAUDAMP18 (Vbus=31V) IR4312’s temperature saturated around 75°C within 30minutes www.irf.com IRAUDAMP18 REV 1.0 Page 8 of 13 CN1 1 3 5 4 2 R3 CT_SGND R4 R5 IRAUDAMP18 REV 1.0 CT_SGND *3.01k 1% C2 1nF C11 C7 2.2nF,50V C12 2.2nF,50V 2.2nF,50V C6 180R R24 R22 180R R16 47.5k 1% R15 47.5k 1% R13 *3.01k 1% C4 1nF *3.01k 1% C3 1nF R14 R18 47.5k 1% C16 VSS D1 D10 C17 1nF C15 1nF 22uF,16V 180R 2.2nF,50V R17 47.5k 1% R21 C14 2.2nF,50V 2.2nF,50V C9 180R R23 R20 180R 2.2nF,50V C13 C8 R19 180R 2.2nF,50V Z1 C5 10uF,10V 5.1V Z2 C10 5.1V 10uF,10V CT_SGND +B R7 220R 1W VAA CT_SGND R6 330 2.2uF CP4 330 2.2uF CP3 INPUT GND VSS R11 *3.01k 1% C1 1nF R12 GND R8 220R 1W CT_SGND 2.2uF330 CP2 2.2uF330 CP1 SD GND FAULT CSD COMP1 IN-1 IN+1 VAA VSS GND IN+2 IN-2 VCC C21 0.1uF,16V COMP2 CLIP DS2 DS1 R27 10K VAA R25 47K 12 11 10 9 8 7 6 5 4 3 2 1 R26 10K VAA 29 10uF,16V C18 -B GND GND 31 26 DS3 1N4148 D2 4.7R R28 10K R29 1N4148 D3 1N4148 D5 1N4148 D4 4.7R R31 IC1 IR4312 4.7R R30 VS1 VN1 VN2 VS2 3 22uF CP5 20 21 22 23 GND Q1 470R 1W 2 R35 11V Z3 R34 4.7k MJD44H11T4G 2.7K C20 0.1uF R33 VCC 0.1uF C19 2.7K R32 C26 0.1uF 1R R42 1R R41 0.1uF C25 +B C28 0.1uF,100V 0.1uF,100V C27 C32 0.47uF, 400V L2 22uH C31 0.47uF, 400V L1 22uH C33 C34 0.1uF, 63V D9 D8 0.1uF, 63V D7 D6 GND LCH 1 2 P1 +B 10R0 Z4 33V R52 10k +B R53 10k +B GND R55 47k +B GND +B C39 GND 2200uF, 25V C38 2200uF, 25V GND CT_PGND INPUT GND R50 NM 0.1uF,100V C37 0.1uF,100V C36 C35 0.1uF R51 47k R47 CT_SGND CT_PGND - + GND CT_PGND RCH 1 2 P2 4 3 OVP 2 6 ON SW SPDT 5 CT_PGND +B SD CT_PGND OFF S1 1 Q2 MMBT5551 18V-31V Version 24 100k R1 100k R2 28 COM 30 NC NC 13 NC VCC 14 COM 15 27 CSH2 CSH1 16 R43 R44 25 VS2 VB2 VB1 17 VS1 18 10, 1W 10, 1W VP2 O O VP1 19 R48 10k, 1/2W SCH_4312 Rev1.2 1 R45 2.2k R46 2.2k Q3 MMBT5551 www.irf.com 10k, 1/2W R49 1 2 P3 Z5 16V R57 47k R56 10k +B UVP Class D, AMP18 IR4312 Schematic Schematic Fig 8 Page 9 of 13 Bill of Materials No Digikey P/N Designator C1, C2, C3, C4, C15, C17 Description CAP CER 1000PF 50V 10% X7R 0603 Quantity Vender 6 Digikey CAP CER 10UF 10V 10% X7R 0805 CAP CER 2200PF 50V 10% X7R 0603 2 Digikey 1 399-1082-1-ND 2 587-2668-1-ND 3 490-1500-1-ND C5, C10 C6, C7, C8, C9, C11, C12, C13, C14 8 Digikey 4 587-1433-1-ND C16 CAP CER 22UF 16V 20% X5R 1206 1 Digikey 5 490-5519-1-ND C18 CAP CER 10UF 16V 10% X6S 0805 1 Digikey 6 311-1140-1-ND C19, C20 CAP CER 0.1UF 50V 10% X7R 0805 2 Digikey 7 311-1142-1-ND C21 1 Digikey 8 445-1418-1-ND C25, C26 2 Digikey 9 4 Digikey 445-1377-1-ND C27, C28, C36, C37 CAP CER 0.1UF 16V 10% X7R 0805 CAP CER 0.1UF 100V 10% X7R 0805 CAP CER 0.1UF 100V 10% X7R 1206 10 495-1315-ND C31, C32 CAP FILM 0.47UF 400VDC RADIAL 2 Digikey 11 BC2054-ND C33, C34 2 Digikey 12 445-1418-1-ND C35 1 Digikey 13 565-1064-ND C38, C39 2 Digikey 14 CP1-3545N-ND CN1 CAP FILM 0.1UF 63VDC RADIAL CAP CER 0.1UF 100V 10% X7R 0805 CAP ALUM 2200UF 25V 20% RADIAL CONN JACK STEREO R/A 5PIN 3.5MM 1 Digikey 15 565-1103-ND CP1, CP2, CP3, CP4 CAP ALUM 2.2UF 50V 20% RADIAL 4 Digikey 16 565-1056-ND Digikey 1N4148W-FDICT-ND CAP ALUM 22UF 25V 20% RADIAL DIODE SWITCH 100V 400MW SOD123 1 17 CP5 D1, D2, D3, D4, D5, D10 6 Digikey 18 160-1181-1-ND DS1 LED RED CLEAR 0603 SMD 1 Digikey 19 160-1183-1-ND DS2 LED GREEN CLEAR 0603 SMD 1 Digikey 20 160-1646-1-ND DS3 1 Digikey 21 IR4312 IC1 1 22 Sagami 7G14A-220M-R L1, L2 2 IR Inductors, Inc 23 281-1414-ND P1, P2, P3 LED BLUE CLEAR 0603 SMD 2 CH PowIRaudio integrated Class D IC Power Inductors Class D Inductor 22uH CONN TERM BLOCK PCB 5.0MM 2POS 3 Digikey 24 MJD44H11T4GOSCT-ND Q1 TRANS PWR NPN 8A 80V DPAK 1 Digikey 25 MMBT5551FSCT-ND Q2, Q3 2 Digikey 26 RMCF0603JT100KCT-ND R1, R2 TRANSISTOR NPN 160V SOT-23 RES 100K OHM 1/10W 5% 0603 SMD 2 Digikey 27 RMCF0603JT330RCT-ND R3, R4, R5, R6 RES 330 OHM 1/10W 5% 0603 SMD 4 Digikey 28 RMCF2512JT220RCT-ND R7, R8 RES 220 OHM 1W 5% 2512 SMD 2 Digikey 29 RHM3.01KCRCT-ND R11, R12, R13, R14 RES 3.01K OHM 1/8W 1% 0805 SMD 4 Digikey 30 311-47.5KCRCT-ND RES 47.5K OHM 1/8W 1% 0805 SMD 4 Digikey 31 RHM180GCT-ND R15, R16, R17, R18 R19, R20, R21, R22, R23, R24 RES 180 OHM 1/10W 5% 0603 SMD 6 Digikey 32 RHM47KGCT-ND R25 RES 47K OHM 1/10W 5% 0603 SMD 1 Digikey 33 RHM10KGCT-ND R26, R27, R29 RES 10K OHM 1/10W 5% 0603 SMD 3 Digikey 34 RMCF0603JT4R70CT-ND R28, R30, R31 RES TF 1/10W 4.7 OHM 5% 0603 3 Digikey 35 RHM2.7KGCT-ND R32, R33 RES 2.7K OHM 1/10W 5% 0603 SMD 2 Digikey 36 311-4.7KARCT-ND R34 RES 4.7K OHM 1/8W 5% 0805 SMD 1 Digikey 37 PT470XCT-ND R35 RES 470 OHM 1W 5% 2512 SMD 1 Digikey 38 P1.0ACT-ND R41, R42 RESISTOR 1.0 OHM 1/8W 5% 0805 2 Digikey 39 541-10.0AFCT-ND R43, R44 RES 10.0 OHM 1W 1% 2512 SMD 2 Digikey 40 RMCF0805JT2K20CT-ND R45, R46 RES 2.2K OHM 1/8W 5% 0805 SMD 2 Digikey 41 541-10KVCT-ND R48, R49 RES 10K OHM 1/2W 5% 1210 SMD 2 Digikey www.irf.com IRAUDAMP18 REV 1.0 Page 10 of 13 42 RMCF0805JT10R0CT-ND R50 RES 10 OHM 1/8W 5% 0805 SMD 1 Digikey 43 RHM47KARCT-ND R51, R55, R57 RES 47K OHM 1/8W 5% 0805 SMD 3 Digikey 44 RHM10KARCT-ND R52, R53, R56 3 Digikey 45 360-1758-ND S1 1 Digikey 46 DDZ5V1BDICT-ND Z1, Z2 RES 10K OHM 1/8W 5% 0805 SMD SWITCH TOGGLE SPDT .4VA SEAL PCB DIODE ZENER 5.1V 500MW SOD123 2 Digikey 47 BZT52C11-FDICT-ND Z3 1 Digikey 48 568-3766-1-ND Z4 1 Digikey 49 BZT52C16-FDICT-ND Z5 1 Digikey DIODE ZENER 11V 500MW SOD123 DIODE ZENER 33V 375MW SOD123F DIODE ZENER 16V 500MW SOD123 PCB Specifications PCB: 1. 2. 3. 4. 5. 6. Two Layers SMT PCB with through holes 1/16 thickness 2/0 OZ Cu FR4 material 10 mil lines and spaces Solder Mask to be Green enamel EMP110 DBG (CARAPACE) or Enthone Endplate DSR-3241or equivalent. 7. Silk Screen to be white epoxy non conductive per IPC–RB 276 Standard. 8. All exposed copper must finished with TIN-LEAD Sn 60 or 63 for 100u inches thick. 9. Tolerance of PCB size shall be 0.010 –0.000 inches 10. Tolerance of all Holes is -.000 + 0.003” 11. PCB acceptance criteria as defined for class II PCB’S standards. www.irf.com IRAUDAMP18 REV 1.0 Page 11 of 13 PCB Layout Top side: Fig9 Bottom side: Fig10 Note: Refer to AN1170 for footprint and board mounting details. www.irf.com IRAUDAMP18 REV 1.0 Page 12 of 13 Revision changes descriptions Revision Rev 1.0 Changes description Released Date May 11, 16 2012 WORLD HEADQUARTERS: 101 N. Sepulveda Blvd., El Segundo, California 90245 Tel: (310) 252-7105 Data and specifications subject to change without notice. 05/16/2012 www.irf.com IRAUDAMP18 REV 1.0 Page 13 of 13