STMicro intros digital audio amplifier SoC

BANGALORE, INDIA: STMicroelectronics has unveiled digital audio-amplifier system-on-chip family suitable for use in dash-mounted sound-system control panels in the car.

Class-D amplifiers achieve about 80 percent higher energy efficiency than analog class-AB amplifiers. This greater efficiency helps reduce the electrical load on the alternator and can allow extra functions or speaker channels within standardized enclosure dimensions. Historically, cost, pc-board size and EMI issues have confined automotive class-D applications to high-power booster amplifiers.

The new audio amplifiers also enhance the audio performance of high-power boosters and integrate circuitry to allow continuous, undistorted playback in vehicles using stop-start engine technology, or in hybrid vehicles as the electrical traction drives and combustion engine switch between various operating modes, claims the company.

The 4x135W FDA4100LV and the 4x50W FDA450LV require no signal conversion or filtering circuitry, saving pc-board space and component count. In addition, engineering challenges such as EMI reduction are addressed inside the chips. The company's patented feedback loop saves the need for a large output filter, and also allows use in diverse OEM and after market products by reducing dependence on speaker type.

The FDA4100LV and FDA450LV feature 4x135W maximum output power (FDA4100LV) or 4x50W (FDA450LV), 4Ω, 2Ω or 1Ω speaker driving capability, unique digital audio input for automotive application, input signal-to-noise ratio and dynamic range: 110dB / 108dB, patented feedback loop design, saving cost and component count, integrated step-up driver, tested for compliance with automotive EMI standards, I2C interface for digital control and diagnostics, stop-start engine compatibility.