AFE4950YBGT

Analog Front End (AFE) Overview

The AFE4950YBGT is an ultra-small analog front-end (AFE) designed for wearable optical heart-rate monitoring, SpO2, and electrical bio-sensing. It supports simultaneous acquisition of up to 24 PPG channels and a single-lead ECG signal. The device features a flexible allocation of 8 LEDs and 4 photodiodes per phase. Key specifications include a system SNR up to 109 dB at 16 µA PD current, low power consumption with typical values of 15 µA for an LED and 20 µA for the receiver, and a 256-sample FIFO. It operates on supplies of 1.7–3.6 V for Rx, 3–5.5 V for Tx, and 1.7–Rx_SUP for IO.

Analog Front End (AFE) Feature Summary

• Simultaneous synchronized acquisition of up to 24 PPG and single-lead ECG signals
• ECG signal chain with input noise of 0.7 µV-rms and programmable INA gain of 11 or 21
• PPG transmitter supporting 8-bit programmable LED current from 25 mA to 250 mA
• PPG receiver with ambient rejection close to 100 dB up to 10 Hz and trans-impedance gain from 3.7 kΩ to 1 MΩ

Analog Front End (AFE) Applications

• Optical Heart-Rate Monitoring (HRM) for Wearables and Hearables
• High performance ECG signal acquisition
• Synchronized PPG and ECG for Blood Pressure estimation
• Heart-rate variability (HRV) analysis
• Pulse oximetry (SpO2) measurements

Analog Front End (AFE) Procurement Notes

Verify the specific ordering suffix 'YBGT' corresponds to the DSBGA package with 250 units per small tape reel. Confirm RoHS compliance and lead finish details (SNAGCU) against the latest TI orderable addendum. Ensure the selected variant matches the required production status and moisture sensitivity level (Level-1).

Analog Front End (AFE) Selection Notes

Select this component when designing for space-constrained wearable devices requiring integrated PPG and ECG capabilities. Consider the 2.6-mm × 2.5-mm DSBGA package dimensions for PCB layout constraints. Evaluate the power supply requirements, specifically the separate Tx (3–5.5 V) and Rx (1.7–3.6 V) rails, to ensure appropriate voltage regulation in the final design.

Analog Front End (AFE) Part Context

The AFE4950 is part of Texas Instruments' family of biosensing analog front-ends tailored for wearable applications. It integrates both optical and electrical sensing chains into a single ultra-small package. The YBGT suffix denotes the specific tape and reel packaging configuration with a standard quantity of 250 units.

Analog Front End (AFE) Replacement Considerations

Public confirmed substitute part numbers are not provided in the source material.