The FDA803S and FDA903S are the latest single-channel fully differential 10W Class D audio power amplifiers in the STMicroelectronics FDA (Pure Digital amplifiers) family. Target applications include emergency road rescue, telematics, and any automotive system that requires voice, music, or prompt messages with an audio channel that produces up to 10W standard output power.
Block diagram
These amplifiers integrate I2S front-end circuitry, a digital core, a 100dB resolution 24-bit digital-to-analog converter (DAC), and a Class D PWM output stage. An on-chip digital audio processor ensures that the amplifier achieves high sound quality in a small area. The internal feedback circuit of the chip is placed in front of the external L-C output filter, which can simplify the circuit design and save space.
Pins description
Both amplifiers have full I2C configuration features and in-run diagnostics, including clipping detection, overheating warning, overcurrent protection and open-circuit load detection, to minimize external component and bill of material costs. The FDA903S also integrates A real-time load current monitor, enabling self-diagnostics to meet ASIL Class A safety requirements for functional safety applications.
Both devices are packaged in QFN32 5mm x 5mm bare underside pads, enabling a compact and economical digital-only design without the need for a radiator. A solution with a small number of devices and no heat sink minimizes the size of the power amplifier. Low static current, compact, lightweight, low power consumption and other product advantages help improve the overall energy efficiency of the vehicle.
Application diagram
Both the FDA803S and the FDA903S have an I2S digital input and Time division Multiplexing (TDM) interface with sampling frequencies ranging from 8kHz to 96kHz to optimize the amplifier's performance when connected to a variety of audio sources. The low sampling frequency of 8kHz to 32kHz enables designers to conserve memory capacity in applications such as warning tone generators
