AFE4432YCHR

Analog Front End (AFE) Overview

The AFE4432YCHR is an integrated analog front-end (AFE) designed for optical bio-sensing applications, including heart-rate monitoring (HRM) and pulse oximetry (SpO2). It supports up to four switching LEDs and three photodiodes (PDs), featuring two LED drivers with 8-bit current control. The device provides a peak system signal-to-noise ratio (SNR) of 115 dB in the 0.5-10 Hz band and operates with a typical receiver current of 12 μA. It includes transimpedance gains ranging from 3.7 kΩ to 1 MΩ, a 160-sample FIFO, and interfaces via SPI or I2C. The component is housed in a 25-pin DSBGA package measuring 1.9 mm by 1.8 mm.

Analog Front End (AFE) Feature Summary

• Supports up to 12 phase sets with flexible allocation of up to 4 LEDs and 3 PDs
• Peak system SNR of 115 dB in the 0.5-10 Hz band for high-accuracy SpO2 measurement
• Transmitter features 8-bit programmable LED current adjustable from 25 mA to 250 mA
• Receiver includes individual ambient and LED offset subtraction DACs with automatic DC cancellation

Analog Front End (AFE) Applications

• Optical Heart-Rate Monitoring (HRM) for wearables and hearables
• Heart-Rate Variability (HRV) analysis
• Pulse Oximetry (SpO2) measurements

Analog Front End (AFE) Procurement Notes

Verify the orderable part number AFE4432YCHR against the manufacturer's latest documentation to confirm active status and packaging specifications. The datasheet indicates this specific suffix corresponds to a tape and reel quantity of 3000 units in a DSBGA YCH package. Confirm environmental compliance details such as RoHS and lead finish directly from the official product folder before procurement.

Analog Front End (AFE) Selection Notes

Select the AFE4432YCHR when designing systems requiring simultaneous multi-wavelength sensing with low power consumption. The device accommodates up to four LEDs and three photodiodes, making it suitable for complex SpO2 and HRM configurations. Ensure the design supports the required supply voltages: 1.7 V to 1.9 V for the receiver and 3 V to 5.5 V for the transmitter. The 1.9 mm x 1.8 mm footprint is ideal for space-constrained wearable form factors.

Analog Front End (AFE) Part Context

The AFE4432YCHR belongs to the AFE4432 family of ultra-small, integrated analog front-ends manufactured by Texas Instruments. This series is specifically engineered for optical bio-sensing, distinguishing itself through high dynamic range transmit-and-receive circuitry and low noise offset DACs. The YCHR suffix denotes the specific commercial temperature range (-20°C to 85°C) and tape-and-reel packaging configuration within the broader AFE4432 product line.

Analog Front End (AFE) Replacement Considerations

Consult the TI datasheet package option addendum for verified alternative part numbers within the AFE4432 family. The AFE4432YCHT is listed as an active alternative with identical electrical characteristics but differs in packaging quantity (250 units per reel versus 3000 units).