AFE4460EVM

The AFE4460 evaluation module (EVM) is a platform for evaluating the AFE4460, which is an analog front end (AFE), for optical biosensing applications, such as heart-rate monitoring and peripheral capillary oxygen saturation (SpO2).

AFE4460 supports up to 32 switching light-emitting diodes (LEDs) and up to four photodiodes (PDs). The AFE has two LED drivers each with 8-bit current control. The device has high-dynamic-range transmit-and-receive circuitry that helps with the sensing of very-small signal levels. Up to 16 signal-phase sets can be defined, each phase set comprising a combination of LED and ambient phases. Low-noise offset digital-to-analog converters (DACs) at the receiver inputs can be automatically controlled to cancel DC from ambient and LED light. The current from each of the four PDs in each phase is converted into voltage by transimpedance amplifiers (TIAs), filtered and then digitized using a common analog-to-digital converter (ADC). The ADC code can be stored in a 256-sample first-in first-out (FIFO) block. The FIFO can be read out using a serial peripheral interface (SPI) or inter-integrated circuit (I²C) interface.

Features

Biosensing AFEs