1 Features

? Integrated signal chains for Bio-Z, EDA, ECG,

PPG

? Synchronized ECG, PPG enables PTT-based BP

? Bio-Z signal acquisition:

– Multi-frequency Body impedance Analysis with

frequency programmable up to 250kHz

– Low frequency excitation mode for EDA/GSR

– Complex (I, Q). Tetrapolar impedance

measurement

– Sine-wave excitation with a 7-bit DAC

– Calibration scheme to compensate for

electrode impedance and achieve accurate

BioZ

? ECG signal acquisition:

– 1-lead ECG signal acquisition up to 4kHz

– Mode to configure as 2-channel ECG

– INA gain programmable from 1.27 - 12.23

– RLD output to set body bias through the third

electrode

– Input noise (0.5-150Hz): 0.5μVrms at gain of

12.23

– >1GΩ input impedance, CMRR>100dB

– Integrated 370 Hz anti-aliasing low pass filter

– AC, DC lead-off detect: 1.6nA to 1μA

? PPG signal acquisition:

– Acquisition of 24 PPG signal sets (LED, AMB)

– Supports PPG sensors at different data rates

– Peak system SNR of 115 dB in 0.5-10Hz band

enables high-accuracy SpO2 measurement

– Low Current for Continuous Operation with a

Typical Value: 19μA for the Receiver

? PPG Transmitter:

– 8-Bit Programmable LED Current with a range

adjustable from 50mA to 300mA

– LED Short Detection

– Support of 16 LEDs in Common Anode

configuration for SpO2, OHRM, Spectroscopy

? PPG Receiver:

– Supports 5 PDs, 4 parallel receive paths

– Noise filtering with programmable bandwidth

– Trans-impedance Gain: 3.7kΩ to 1MΩ

– 8-bit Ambient Offset Subtraction DAC up to

256μA

– 9-bit LED Offset Subtraction DAC up to 64μA

– Digital Ambient Subtraction at ADC Output

? EDA Signal Acquisition:

– Low-power continuous EDA and PPG

acquisition using the ECG receiver

– Independent data rates for EDA and PPG

acquisition with optimized power cycling

– High-accuracy EDA signal chain for spot-check

EDA using the BIA signal chain

? Supports external clock and internal oscillator

? Option to operate 2 AFEs in parallel

? Option to configure the 5th PD input as a general

purpose voltage measurement channel

? FIFO with 384-sample Depth, SPI?

? Supplies: RX,:1.7-1.9V, I/O: 1.15-1.9V, TX:3-5.5V

2 Applications

? Bio-Z, ECG, PPG, EDA on wearable devices

? Impedance spectroscopy

? Weight scales with body composition

? Current, voltage, impedance sensing

3 Description

The AFE4510 is a versatile signal acquisition system

that supports acquiring PPG, EDA, ECG, and Bioimpedance

signals. A PPG signal chain comprises a

current driver for LEDs and a receiver that senses

the signal from PDs. An ECG receiver with a Rightleg

drive (RLD) can acquire a single-lead ECG from

a pair of electrodes. An impedance measurement

signal chain with integrated excitation & sense can be

used for applications like BIA, EDA, and Impedance

spectroscopy. The outputs of the various signal chains

are digitized by a common ADC and stored in a FIFO

which can be read out using an SPI interface