Description
The AS7056 Biosignal Sensor Analog Frontend (AFE) is the next generation Vital Sign Sensor. It
enables the user to detect biosignals such as photoplethysmogram (PPG) and pulse transit time
(PTT), as well as proximity. PPG is the most used HRM method. It measures the pulse rate - by
sampling light modulated by the blood vessels, which expand and contract as blood pulses through
them. Apart from HRM/HRV, optical Blood Pressure and SpO2 are also enabled by the two
independent working photodiode inputs of the AS7056. The AS7056 is a size and performances
optimized analog frontend to support space-limited applications such as in-ear vital sign monitoring.
The AS7056 provides two LEDs and one VCSEL driver outputs, samples up to three photodiode
inputs, and supports proximity detection integrated into one of the PPG signal channels. This enables
high flexibility for several LED and photodiode arrangements in different applications. Furthermore, the
AS7056 Biosignal Sensor Analog Frontend provides two ADC channels for simultaneous PPG
measurements and an automatic photodiode offset control.
The AS7056’s low-power design and small form factor are particularly well-suited for application in
earbuds, fitness bands, smartwatches, sports watches, and smart patches. In these cases, board
space is limited, and users look for extended, multi-day intervals between battery recharges. A thin
package dimension makes the AS7056 suitable for height-constrained solutions like earbuds.

Features
2 LED + 1 VCSEL driver and 3 photodiode input
pins.
Small Wafer-Level-Chip-Scale-Package
(WLCSP).
Two synchronized PPG acquisition channels.
Two independent, programmable sequence
blocks inside the PPG signal acquisition.
Low noise analog optical front-end.
Hardware sequencer to offload processor.
Adjustable LED driver with current control.