原标题：IR IRAUDAMP8 4路120W D类音频功率放大器设计方案

　　IR 公司的IRAUDAMP8是采用IRS2093M D类音频控制器和DirectFET MOSFET IRF6665的 4路120W D类音频功率放大器,包括了所有所需的电源,每路能向4欧姆提供120W,效率为90%.在60W和4欧姆时THD+N为0.012%,具有多种保护特性,包括高边和低边的过流保护(OCP),欠压保护(UVP)以及过压保护,超温保护(OTP),可用在AV接收器,家庭影院系统,有源扬声器,音乐仪表放大器,汽车电子放大器以及迷你立体声音响等.本文介绍了IRAUDAMP8的主要特性和指标, D类放大器简化方框图和电路图以及放大器所用电子元件和`机械元件清单(BOM).

　　IRAUDAMP8:

　　120W x 4 Channel Class D Audio Power Amplifier Using the IRS2093M and IRF6665

　　图1. IRAUDAMP8参考设计完形图

　　The IRAUDAMP8 Demo board is a reference design which uses only one IC (IRS2093M) to derive appropriate input signals, amplify the audio input, and achieve a four-channel 120 W/ch (4Ω) half-bridge Class D audio power amplifier. The reference design demonstrates how to use the IRS2093M Class D audio controller and gate driver IC, implement protection circuits, and design an optimum PCB layout using IRF6665 DirectFET MOSFETs. The reference design contains all the required housekeeping power supplies for ease of use. The four-channel design is scalable, for power and number of channels.

　　The IRAUDAMP8 features a 4CH self-oscillating type PWM modulator for the smallest space, highest performance and robust design. This topology represents an analog version of a secondorder sigma-delta modulation having a Class D switching stage inside the loop. The benefit of the sigma-delta modulation, in comparison to the carrier-signal based modulation, is that all the error in the audible frequency range is shifted to the inaudible upper-frequency range by nature of its operation. Also, sigma-delta modulation allows a designer to apply a sufficient amount of error correction.

　　IRAUDAMP8应用:

　　AV receivers

　　Home theater systems

　　Mini component stereos

　　Powered speakers

　　Sub-woofers

　　Musical Instrument amplifiers

　　Automotive after market amplifiers

　　IRAUDAMP8主要特性:

　　Output Power: 120W x 4 channels,

　　Residual Noise: 200V, IHF-A weighted, AES-17 filter

　　Distortion: 0.012% THD+N @ 60W, 4Ω

　　Efficiency: 90% @ 120W, 4Ω, single-channel driven, Class D stage

　　Multiple Protection Features: 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)

　　PWM Modulator: Self-oscillating half-bridge topology with optional clock synchronization

　　IRAUDAMP8主要指标:

　　General Test Conditions (unless otherwise noted) Notes / Conditions

　　Supply Voltages ±35V

　　Load Impedance 4Ω

　　Self-Oscillating Frequency 400kHz No input signal, Adjustable

　　Gain Setting 26.5dB 1Vrms input yields rated power

　　Electrical Data Typical Notes / Conditions

　　IR Devices Used IRS2093M Audio Controller and Gate-Driver,

　　IRF6665 DirectFET MOSFETs

　　Modulator Self-oscillating, second order sigma-delta modulation, analog input

　　Power Supply Range ± 25V to ±35V Bipolar power supply

　　Output Power CH1-4: (1% THD+N) 120W 1kHz

　　Output Power CH1-4: (10% THD+N) 170W 1kHz

　　Rated Load Impedance 8-4Ω Resistive load

　　Standby Supply Current ±100mA No input signal

　　Total Idle Power Consumption 7W No input signal

　　Channel Efficiency 90% Single-channel driven,

　　120W, Class D stage

　　IRAUDAMP8 D类放大器电元件清单(BOM):

　　IRAUDAMP8 D类放大器机械零件清单: