Audio Amplifiers

STPA003OD-4WX

STPA003OD-4WX - 4x52W Quad Class AB Amplifier | STMicroelectronics

The STPA003OD-4WX is a quad-channel Class AB audio power amplifier from STMicroelectronics, designed for high-power car radio applications. It delivers up to 52W per channel into 4Ω loads (at 14.4V, 10% THD) and operates from a supply voltage range of 6V to 18V. The device is housed in a 25-pin Flexiwatt25 package, which is a vertical, through-hole power package with an exposed metal tab for efficient heat dissipation. A Class AB audio amplifier is a linear amplifier that conducts current through both output devices for more than half but less than the full cycle, offering a compromise between the efficiency of Class B and the linearity of Class A. In automotive audio systems, Class AB amplifiers are widely used for their low distortion and good sound quality, making them suitable for driving speakers in head units and external amplifiers. The STPA003OD-4WX fits into the hierarchy of audio power amplifiers, which are a subset of analog integrated circuits used in consumer and automotive entertainment systems. Key features of the STPA003OD-4WX include a high output power of 52W per channel, a wide supply voltage range, and a low quiescent current for reduced power consumption during standby. It also features standby and mute functions for power management, and a full set of protections including short-circuit, thermal, and load-dump protection. The device is designed to meet automotive-grade quality standards, ensuring reliable operation in harsh environments. Technically, the STPA003OD-4WX uses a complementary NPN/PNP output stage with a Darlington configuration to achieve high current gain and low output impedance. The amplifier incorporates a precision bandgap reference for stable biasing and a thermal shutdown circuit that protects the device from overheating. The Flexiwatt25 package provides a low thermal resistance of 1.5°C/W, allowing the amplifier to dissipate up to 100W of power without external heatsinking in moderate conditions. Typical applications include car radio head units, external automotive amplifiers, and other in-vehicle audio systems where high power and low distortion are required. The device is also suitable for marine and off-road vehicle audio systems that demand robust performance. When designing with this amplifier, ensure adequate heatsinking and proper PCB layout to manage the high power dissipation, and use the standby and mute pins for efficient power management in battery-powered systems.