Fast-track to successful Class-D amplifier design

International Rectifier has introduced the IRAUDAMP4 reference design to accelerate completion of robust and reliable Class-D amplifiers incorporating critical protection features and housekeeping functions.

The two-channel, 120W design is scalable for power and number of channels, to solve the entire mid-voltage range of mid- and highpower amplifiers. No heatsink is required under normal operating conditions.

Built-in protection features include overcurrent, over-voltage, under-voltage and overtemperature protection, as well as DC protection. Housekeeping functions include a ±5V supply for analogue signal processing in the preamplifier and a 12V supply referenced to -B for the Class-D gate driver stage. The IRAUDAMP4 reference design features half-bridge topology and combines the IRS20955 200V digital audio driver IC with IR’s IRF6645 digital audio MOSFETs. These use DirectFET® package technology to enhance switching performance and reduce EMI. The IRS20955 features a floating PWM input designed specifically for Class-D audio amplifier applications, requires no external shunt resistors for over-current detection, and features internal dead-time generation for lower THD and lower audio noise floor.

The reference design has demonstrated 96% efficiency at 120W and 4Ω output impedance.

 

FEATURES 50% smaller footprint than typical circuit designs Reduced total system cost 26.8dB gain Programmable reset timer

APPLICATIONS Home theatre Professional amplifiers Musical instruments In-car entertainment

 

 

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