AFE44S30YZT, Analog Front End - AFE Ultra-low-power integrated analog front end (AFE) for wearable optical biosensing with FIFO and SPI 30-D

AFE44S30 Ultra-Low-Power Integrated AFE
Texas Instruments AFE44S30 Ultra-Low-Power Integrated Analog Front End (AFE) is for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO 2 ). The device supports up to eight 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 SPI interface. The AFE also has a fully-integrated LED driver with an 8-bit current control. The AFE44S30 has a high dynamic range transmit-and-receive circuitry that helps with the sensing of very small signal levels.