Multimodal Sensor Front End Data Sheet ADPD4100/ADPD4101 FEATURES GENERAL DESCRIPTION Multimodal analog front end The ADPD4100/ADPD4101 operate as a complete multimodal 8 input channels with multiple operation modes for various sensor front end, stimulating up to eight light emitting diodes sensor measurements (LEDs) and measuring the return signal on up to eight separate Dual-channel processing with simultaneous sampling current inputs. Twelve time slots are available, enabling 12 separate 12 programmable time slots for synchronized sensor measurements per sampling period. measurements 2 The data output and functional configuration utilize an I C Flexible input multiplexing to support differential and interface on the ADPD4101 or a serial port interface (SPI) on single-ended sensor measurements the ADPD4100. The control circuitry includes flexible LED 8 LED drivers, 4 of which can be driven simultaneously signaling and synchronous detection. The devices use a 1.8 V Flexible sampling rate from 0.004 Hz to 9 kHz using internal analog core and 1.8 V/3.3 V compatible digital input/output (I/O). oscillators On-chip digital filtering The analog front end (AFE) rejects signal offsets and corruption SNR of transmit and receive signal chain: 100 dB from asynchronous modulated interference, typically from AC ambient light rejection: 60 dB up to 1 kHz ambient light, eliminating the need for optical filters or externally 400 mA total LED peak drive current controlled dc cancellation circuitry. Multiple operating modes Total system power dissipation: 30 W (combined LED and are provided, enabling the ADPD4100/ADPD4101 to be a sensor AFE power), continuous PPG measurement at 75 dB SNR, hub for synchronous measurements of photodiodes, biopotential 25 Hz ODR, 100 nA/mA CTR electrodes, resistance, capacitance, and temperature sensors. The 2 SPI and I C communications supported multiple operation modes accommodate various sensor measure- 512-byte FIFO size ments, including, but not limited to, photoplethysmography (PPG), electrocardiography (ECG), electrodermal activity APPLICATIONS (EDA), impedance, capacitance, temperature, gas detection, Wearable health and fitness monitors: heart rate monitors smoke detection, and aerosol detection for various healthcare, (HRMs), heart rate variability (HRV), stress, blood pressure industrial, and consumer applications. estimation, SpO2, hydration, body composition The ADPD4100/ADPD4101 are available in a 3.11 mm Industrial monitoring: CO, CO2, smoke, and aerosol detection 2.14 mm, 0.4 mm pitch, 33-ball WLCSP and 35-ball WLCSP. Home patient monitoring FUNCTIONAL BLOCK DIAGRAM AVDD DVDD1 ADPD4100/ADPD4101 LED4B DVDD2 LED3B IOVDD LED LEVEL LED2B AND LED1B LED MUX CONTROL AGND LED4A DRIVERS DGND LED3A IOGND HIGH LED2A FREQUENCY LED1A CS AND LOW FREQUENCY SCLK OSCILLATORS LGND MOSI DIGITAL PROCESSING, INTEGRATOR MISO TIMING INTERFACE AND TIMING CONTROL, SCL IN1 CH 1 SIGNAL FIFO, PROGRAM AND SDA IN2 CONDITIONING DATA REGISTERS, IN3 ADC COMMUNICATIONS GPIO0 IN4 TIA VREF GPIO1 IN5 GPIO2 IN6 CH 2 SIGNAL GPIO3 IN7 CONDITIONING IN8 VREF INTEGRATOR TIMING VC1 VC1 VOLTAGE VREF VC2 VC2 REFERENCES TIA VREF NOTES V ICM 1. CS, SCLK, MOSI, AND MISO PINS ARE ON THE ADPD4100. 2. SCL AND SDA PINS ARE ON THE ADPD4101. 3. TIA VREF IS THE INTERNAL VOLTAGE REFERENCE SIGNAL FOR THE TRANSIMPEDANCE AMPLIFIER. Figure 1. Rev. 0 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 2020 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 23297-001ADPD4100/ADPD4101 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Time Slot Operation .................................................................. 23 Applications ....................................................................................... 1 Execution Modes ........................................................................ 24 General Description ......................................................................... 1 Host Interface .............................................................................. 24 Functional Block Diagram .............................................................. 1 Applications Information .............................................................. 28 Revision History ............................................................................... 2 Operating Mode Overview ....................................................... 28 Specifications ..................................................................................... 3 Analog Integration Mode .......................................................... 28 Temperature and Power Specifications ..................................... 3 Digital Integration Mode ........................................................... 40 Performance Specifications ......................................................... 4 TIA ADC Mode .......................................................................... 42 Digital Specifications ................................................................... 6 Protecting Against TIA Saturation in Normal Operation .... 42 Timing Specifications .................................................................. 6 ECG Measurement with the ADPD4100/ADPD4101 .......... 44 Absolute Maximum Ratings ............................................................ 9 Register Map ................................................................................... 51 Thermal Resistance ...................................................................... 9 Register Details ............................................................................... 70 Electrostatic Discharge (ESD) Ratings ...................................... 9 Global Configuration Registers ................................................ 70 ESD Caution .................................................................................. 9 Interrupt Status and Control Registers .................................... 72 Pin Configurations and Function Descriptions ......................... 10 Threshold Setup and Control Registers .................................. 82 Typical Performance Characteristics ........................................... 13 Clock and Timestamp Setup and Control Registers.............. 84 Theory of Operation ...................................................................... 15 System Registers ......................................................................... 84 Introduction ................................................................................ 15 I/O Setup and Control Registers .............................................. 86 Analog Signal Path ..................................................................... 15 Time Slot Configuration Registers ........................................... 89 LED Drivers ................................................................................ 16 AFE Timing Setup Registers ..................................................... 94 Determining C ...................................................................... 17 LED Control and Timing Registers ......................................... 96 VLED Datapath, Decimation, Subsampling, and FIFO .................... 18 ADC Offset Registers ................................................................. 97 Clocking ....................................................................................... 21 Output Data Registers ............................................................... 97 Time Stamp Operation .............................................................. 22 Outline Dimensions ..................................................................... 100 Low Frequency Oscillator Calibration .................................... 22 Ordering Guide ........................................................................ 101 High Frequency Oscillator Calibration ................................... 22 REVISION HISTORY 6/2020Revision 0: Initial Version Rev. 0 Page 2 of 101