Stmicro's TDA7901 gauge power amplifier is monolithic integrated with a Class G power amplifier switch tube step-down controller and supports HD audio, a unique feature combination that delivers an excellent auditory experience and high energy efficiency. In Class G amplification, the TDA7901 step-down controller automatically optimizes the supply voltage of the bridging load (BTL) power level based on the audio signal level, resulting in smooth analog audio that is close to the energy efficiency of a Class D power amplifier at normal volume.

     Because the power dissipation is much lower than traditional Class A/B amplifiers, the radiator requirement is reduced. Monolithic integrated step-down controllers help reduce system weight, reduce bill of material costs, and simplify circuit design without the need to develop voltage rail control firmware.

     The TDA7901 is suitable for many onboard information (IVI) systems, e.g., main engine, intelligent cockpit systems, external power amplifier, etc. The amplifier delivers a complete real-time diagnostic signal, including real-time monitoring of load current through the I2S or I2C interface, enabling ASIL-A certification for safety-related applications such as tone generators and low-speed tone systems for electric vehicles (AVAS). The amplifier chip also provides a digital impedance meter, ensuring that audio systems using the TDA7901 can meet the most demanding requirements of automotive Oems.

     With I2S digital input and smart four-bridge BTL output, the TDA7901 provides 4x 43W audio power output (14.4V at saturation output when driving a 4Ω load). The amplifier uses 80kHz bandwidth to process HD audio. The wide supply voltage of 4.5V to 18.5V prevents audio interruption during engine start-stop and other common voltage transients