Integrated Optical Module with Ambient Light Rejection and Three LEDs ADPD174GGI Data Sheet FEATURES GENERAL DESCRIPTION 2.8 mm x 6.5 mm module with integrated optical components 2 green LEDs located on either side of the photodiode, 1 infrared LED, and 1 photodiode True 3-channel 250 mA LED driver Separate LED and AFE settings for each channel Dual data registers for each LED return signal 14-bit ADC 20-bit burst accumulator enabling 20 bits per sample period On-board sample to sample accumulator enabling up to 27 bits per data read Custom optical package made to work under a glass window Optimized SNR for signal limited cases The ADPD174GGI is a complete photometric system designed to measure optical signals from ambient light and from synchronous reflected LED pulses. Synchronous measurement offers best-inclass rejection of ambient light interference, both dc and ac. The module integrates a highly efficient photometric front end, three LEDs, and a photodiode (PD). All of these items are housed in a custom package that prevents light from going directly from the LED to the photodiode without first entering the subject. The front end of the ASIC consists of a control block, a 14-bit analog-to-digital converter (ADC) with a 20-bit burst accumulator, and three flexible, independently configurable LED drivers. The control circuitry includes flexible LED signaling and synchronous detection. The analog front end (AFE) features best-in-class rejection of signal offset and corruption due to modulated interference commonly caused by ambient light. The data output and functional configuration occur over a 1.8 V I2C interface. APPLICATIONS Optical heart rate monitoring Reflective SpO2 measurement FUNCTIONAL BLOCK DIAGRAM VDD2 VDD1 ADPD174GGI PHOTODIODE ANALOG BLOCK AGND VREF CH. 1 VLED2 TIA IR VLED1 AMBIENT LIGHT REJECTION AFE GAIN 14-BIT ADC VBIAS GREEN AFE CONFI GUR ATI ON, TIME SLOT A AFE CONFI GUR ATI ON, TIME SLOT B AFE: SIGNAL CONDITIONING LED3/DNC LED2 LED1/DNC 1F TIME SLOT A DATA LEDs LED3 DRIVER LED2 DRIVER LED3 LEVEL AND TIMING CONTROL LED1 DRIVER LED2 LEVEL AND TIMING CONTROL TIME SLOT B DATA SDA SCL INT DGND DIGITAL INTERFACE AND CONTROL LED1 LEVEL AND TIMING CONTROL NOTES 1. DNC = DO NOT CONNECT. DO NOT CONNECT TO THIS PIN WHEN USING INTERNAL LEDs. 13519-001 LGND Figure 1. For more information about the ADPD174GGI, contact Analog Devices, Inc., at optical_sensors@analog.com. Rev. SpA Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 (c)2015 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com ADPD174GGI* Product Page Quick Links Last Content Update: 09/02/2016 Comparable Parts Design Resources View a parametric search of comparable parts * * * * * Documentation Data Sheet * ADPD174GGI: Integrated Optical Module with Ambient Light Rejection and Three LEDs Data Sheet Reference Materials Technical Articles * When Every A Counts! ADPD174 Material Declaration ADPD174GGI Material Declaration PCN-PDN Information Quality And Reliability Symbols and Footprints Discussions View all ADPD174GGI EngineerZone Discussions Sample and Buy Visit the product page to see pricing options Technical Support Submit a technical question or find your regional support number * This page was dynamically generated by Analog Devices, Inc. and inserted into this data sheet. Note: Dynamic changes to the content on this page does not constitute a change to the revision number of the product data sheet. This content may be frequently modified. ADPD174GGI Data Sheet NOTES (c)2015 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D13519F-0-12/15(SpA) Rev. SpA | Page 2 of 2