The FDA803S and the FDA903S are the most recent one-channel, fully differential 10W ClassD audio power amplifiers that belong to the STMicroelectronics FDA (fully digital amplifier) family of. They are specifically designed for automotive applications, such as eCall or telematics, as well as where an audio channel has to reproduce human voices music, sound, or warning messages with a standard output power that is up to 10W. The amplifiers include an I2S front-end digital core, a digital core, a 24 bit digital-to-analog converter (DAC) with a 100dB resolution and a PWM output stage in class-D. Digital audio processing integrated guarantees excellent sound quality in an extremely compact circuit footprint.
Feedback inside the chip, prior to an external output filter for L-C makes circuit design simpler and reduces the space. With complete I2C configuration and diagnostics in-play which include clipping detection, thermal warning, overcurrent protection and detection of open loads, these amplifiers cut down on the use of external components and bills-of-materials. The FDA903S also includes a real-time load-current monitor, which allows for self-diagnostic capabilities that are compatible with the requirements of functional safety applications as high as ASIL A.
The two devices are available as QFN32 5mmx5mm pad-down designs that allow for an affordable and compact, completely digital design, without the requirement of the use of a heatsink. Low component count and the absence of a heatsink reduce the weight of power amplifiers made with these ICs. In addition, due to the low power consumption, the possibility to reduce weight, size and power consumption, they contribute to enhancing the efficiency of your vehicle overall. Both FDA803S and FDA903S come with the I2S digital input as well as a time-division multiplication (TDM) interface. They can be set up to use a variety of sampling frequencies ranging from 8kHz to 96kHz, to enhance the performance of an array of sources for audio. Lower sampling frequencies between 8kHz and 32kHz, allow designers to conserve memory in programs like the warning tones generators.