AFE44I3x Ultra-Low-Power Analog Front End (AFE)
Texas Instruments AFE44I3x Ultra-Low-Power Integrated Analog Front End is designed for optical bio-sensing applications, such as heart-rate monitoring (HRM) and peripheral capillary oxygen saturation (SpO2). The AFE44I3x supports up to six switching light-emitting diodes (LEDs) and up to four photodiodes. Up to 24 signal phases can be defined, and the signal can be acquired from each phase in a synchronized manner. The current from the photodiode is converted into a voltage by the transimpedance amplifier (TIA) and digitized using an analog-to-digital converter (ADC). The ADC code can be stored in a 128-sample First-In, First-Out (FIFO) block. The FIFO can be read out using an I2C interface.
