CRD44600-PH-FB Stereo 100 W PWM Amplifier Reference Design controller. This reference design implements a two- Features channel amplifier which delivers 100 W per full-bridge z Two full-bridge channels, 100 W each channel into 8 loads using a single +50 V supply (at 1% THD+N). A 155 W unregulated linear power supply z 106 dB Dynamic Range - both channels is used to power the CRD44600-PH-FB. z 0.015% THD+N at 1 W As shown below, the CS44600 IC takes two stereo digi- z Power Supply Rejection (PSR) feedback tal audio PCM inputs and converts them to PWM allowing amplifier to operate from low cost outputs. This 64-pin LQFP PWM controller provides an linear unregulated power supplies integrated sample rate converter for 32 kHz-192 kHz in- z Spread Spectrum Modulation - Reduces put sample rate support, volume up/down, speaker load Modulation Energy compensation, peak limiting to prevent amplifier clipping, z Passes CISPR and FCC requirements for power supply ripple compensation, and AM frequency interference elimination. radiated and power line conducted emissions This reference design uses the the Philips TDA8939, an z Independent peak signal limiting per channel integrated power stage back end for digital amplifiers (two TDA8939 parts configured as full-bridges are used z Thermal and over-current protection for this two-channel design). Current limiting and ther- z > 85% amplifier efficiency mal protection are provided by the TDA8939. z Works with GUI to configure the board nd The inductor/capacitor 2 order low pass filter (LPF) re- z Demonstrates recommended layout and moves high frequency components from the output grounding arrangements signal effectively converting it from digital to analog. Description ORDERING INFORMATION The CRD44600-PH-FB PWM Amplifier demonstrates CRD44600-PH-FB Reference Design the CS44600, Cirrus multi-channel pure digital PWM I PSR Circuitry +50 V CS4461 ADC 155W Unregulated +50 V Linear Power Supply +50 V Channel 1 Philips LPF 8 TDA8939 PCM Clocks & Data Audio Inputs and GUI CS44600 Interface (PWM Controller) +50 V 2 I C Host Control Channel 2 Philips LPF 8 TDA8939 Cirrus Logic, Inc. Copyright Cirrus Logic, Inc. 2005 www.cirrus.com MAR 05 (All Rights Reserved) DS633RD1 1CRD44600-PH-FB TABLE OF CONTENTS 1. SYSTEM OVERVIEW ............................................................................................................... 3 1.1 CS44600 PWM Modulator ................................................................................................. 3 1.2 CS4461 PSR Feedback ADC ............................................................................................ 3 1.3 TDA8939 Power Stage ...................................................................................................... 3 1.4 CS8416 Digital Audio Receiver .......................................................................................... 3 1.5 CS5341 Analog to Digital Converter .................................................................................. 3 1.6 Control Port Interface and GUI .......................................................................................... 4 1.7 Unregulated Linear Power Supply .....................................................................................4 2. GUI CONTROL ......................................................................................................................... 5 2.1 CS44600 Dialog Tab .......................................................................................................... 5 2.2 Advanced Register Debug Tab .......................................................................................... 6 3. POWER SUPPLY ..................................................................................................................... 8 3.1 Power Supply Ratings ........................................................................................................ 8 3.2 Power Supply Decoupling .................................................................................................. 8 4. ELECTROMAGNETIC INTERFERENCE (EMI) ....................................................................... 9 4.1 Suppression of EMI at the Source ..................................................................................... 9 4.2 EMI Testing ........................................................................................................................ 9 5. CRD44600-PH-FB SCHEMATICS ......................................................................................... 14 6. CRD44600-PH-FB POWER SUPPLY SCHEMATICS ........................................................... 19 7. CRD44600-PH-FB LAYOUT ................................................................................................... 20 8. CRD44600-PH-FB BILL OF MATERIALS .......................................................................23 9. TYPICAL PERFORMANCE PLOTS ....................................................................................... 25 10. REVISION HISTORY ............................................................................................................ 30 LIST OF FIGURES Figure 1. CS44600 Dialog Tab........................................................................................................ 5 Figure 2. Advanced Register Debug Tab - CS44600...................................................................... 6 Figure 3. Advanced Register Debug Tab - CS8416........................................................................ 7 Figure 4. EMI Testing Setup.......................................................................................................... 11 Figure 5. EMI Testing Setup, Close-up ......................................................................................... 11 Figure 6. Radiated EMI Testing Results- 30 MHz to 200 MHz...................................................... 12 Figure 7. Radiated EMI Testing Results- 200 MHz to 1 GHz........................................................ 12 Figure 8. Conducted Power Line Testing Results ......................................................................... 13 Figure 9. Audio Inputs ................................................................................................................... 14 Figure 10. CS44600 ...................................................................................................................... 15 Figure 11. PSR Feedback............................................................................................................. 16 Figure 12. Left/Right Channels...................................................................................................... 17 Figure 13. Control Port and Power................................................................................................ 18 Figure 14. Power Supply............................................................................................................... 19 Figure 15. Silk Screen Top............................................................................................................ 20 Figure 16. Topside Layer .............................................................................................................. 21 Figure 17. Bottomside Layer ......................................................................................................... 22 Figure 18. Frequency Response...................................................................................................25 Figure 19. THD+N vs. Frequency at 1 W, 10 W, and 50 W .......................................................... 26 Figure 20. THD+N vs. Power at 1 kHz .......................................................................................... 27 Figure 21. FFT at -60 dBFS and 1 kHz ......................................................................................... 28 Figure 22. FFT at -1 dBFS and 1 kHz. Red = PSR Feedback Off. Blue = PSR Feedback On ..... 29 LIST OF TABLES 2 MAR 05 DS633RD1