Page 37 - EngineerIt August 2021

MEASUREMENT

The ADPD1080 is an integrated optical AFE with three LED
drive channels and two PD current input channels in a 17-ball,
2.5 mm × 1.4 mm WLLCSP. This AFE is ideal for custom design
low channel count PPG products where board space is critical. n

References
1. Toshiyo Tamura. “Current Progress of Photoplethysmography and SpO 2
for Health Monitoring.” Biomedical Engineering Letters, February 2019.
2. Jihyoung Lee, Kenta Matsumura, Ken-Ichi Yamakoshi, Peter Rolfe,
Shinobu Tanaka, and Takehiro Yamakoshi. “Comparison Between
Red. Green and Blue Light Reflection Photoplethysmography for
Heart Rate Monitoring During Motion.” 2013 35th Annual International
Conference of the IEEE Engineering in Medicine and Biology Society
(EMBC), July 2013.

About the author
Robert Finnerty is a systems applications engineer working for the Digital
Figure 7. ADPD4100 simultaneous red (right) and IR (left) PPG Healthcare Group based in Limerick, Ireland. He works closely with
measurement. the Vital Signs Monitoring Group, focusing on optical and impedance
measurement solutions. Rob joined the precision converters group within
2.8 mm × 5 mm package. The spacing between the LEDs and PD ADI in 2012 and has focused on low bandwidth precision measurement.
have been optimised to give the best signal-to-noise ratio for SpO 2 He holds a bachelor’s degree in electronic and electrical engineering
high accuracy PPG measurements. This module allows users to (B.E.E.E) from National University of Ireland Galway (NUIG). He can be
quickly skip the design challenges associated with LED and PD reached at rob.finnerty@analog.com.
placement and spacing to achieve optimal power-to-noise ratios.
The ADPD144RI has been mechanically optimised to reduce Analog Devices (www.analog.com) is represented in South Africa
optical crosstalk as much as possible. This provides a solid solution, by Altron Arrow. For more information contact Conrad Coetzee at
even when the sensor is placed under a single glass window. ccoetzee@arrow.altech.co.za