AFE4900YZT

The AFE4900YZT from Texas Instruments is an ultra-low-power integrated analog front end (AFE) designed for wearable optical and electrical biosensing applications. It supports synchronized PPG and ECG signal acquisition with data rates up to 1 kHz for PPG and up to 4 kHz for ECG. The device includes a 1-lead ECG signal chain with RLD bias and a PPG receiver supporting three time-multiplexed photodiode inputs.

Key electrical specifications include a programmable INA gain from 2.15 to 12.92, transimpedance gain from 10 kΩ to 2 MΩ, and a dynamic range of up to 100 dB. The input noise is 2.5 µVrms at 1 kHz data rate and 1.25 µVrms at 4 kHz data rate. The device operates with supply voltages of 1.8 V to 1.9 V (Rx LDO bypass), 2.0 V to 3.6 V (Rx LDO enabled), 3 V to 5.25 V (Tx), and 1.7 V to Rx_SUP (IO).

The AFE4900YZT is housed in a 30-DSBGA package measuring 2.6 mm × 2.1 mm with a 0.4 mm pitch, suitable for space-constrained wearable designs. It features a 128-sample FIFO for ECG and PPG data, and supports I2C and SPI interfaces selectable by pin. The device is rated for an operating temperature range of -20°C to 70°C.