AFE4900 Ultra-Low-Power Integrated AFE for Wearable Optical, Electrical Biosensing Evaluation Module
The AFE4900 is an analog front end (AFE) for optical biosensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO2). The device supports four switching light-emitting diodes (LEDs) and three photodiodes. The current from the photodiode is converted into 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 FIFO with programmable depth. The FIFO depth can be partitioned to accommodate the phases that need to be stored. The FIFO can be read out using either an I2C or SPI interface. The AFE also has a fully-integrated LED driver with an 8-bit current control. The device can be clocked by an external clock or internal oscillator. The device communicates to an external host processor using an SPI/I2C interface. The purpose of the AFE4900 evaluation module (EVM) is to expedite evaluation and system development activities related to the AFE4900 device.
- Acquire data at up to 1000 SPS in evaluation mode
- USB-based power and PC application connectivity
- Access to all AFE4900 registers via an easy-to-use GUI
- USB-based firmware upgrade option