50 A, 2 mm 1.7 mm WLCSP, Low Noise, Heart Rate Monitor for Wearable Products Data Sheet AD8233 FEATURES FUNCTIONAL BLOCK DIAGRAM A4 B4 A3 A2 A1 Fully integrated, single-lead ECG front end HPSENSE IAOUT REFIN +V GND S Low quiescent supply current: 50 A (typical) HPDRIVE A5 FR B3 Leads on/off detection while in shutdown (<1 A) S1 10k A3 +IN Common-mode rejection ratio: 80 dB (dc to 60 Hz) B5 2-electrode and 3-electrode configurations AC/DC B2 IA IN C5 High signal gain (G = 100) with dc blocking capabilities 2-pole adjustable high-pass filter SDN B1 150k AD8233 Accepts up to 300 mV of half cell potential C4 Fast restore feature improves filter settling RLDFB RLD SDN C2 Uncommitted op amp D5 A2 3-pole adjustable low-pass filter with adjustable gain LOD RLD LEADS OFF C C1 DETECTION Integrated RLD amplifier with shutdown S2 Single-supply operation: 1.7 V to 3.5 V 10k A1 Integrated reference buffer generates virtual ground SW OPAMP+ REFOUT OPAMP OUT Rail-to-rail output D4 D3 C3 D2 D1 Internal RFI filter Figure 1. 20-Ball WLCSP 8 kV HBM ESD rating To improve the common-mode rejection of the line frequencies Shutdown pin 2 mm 1.7 mm WLCSP package in the system and other undesired interferences, the AD8233 includes a right leg drive (RLD) amplifier for driven electrode APPLICATIONS applications. Fitness and activity heart rate monitors The AD8233 includes a fast restore function that reduces the Portable ECG duration of the otherwise long settling tails of the high-pass Wearable and remote health monitors filters. After an abrupt signal change that rails the amplifier Gaming peripherals (such as a leads off condition), the AD8233 automatically adjusts Biopotential signal acquisition, such as EMG or EEG to a higher filter cutoff. This feature allows the AD8233 to GENERAL DESCRIPTION recover quickly, and therefore, to take valid measurements soon after connecting the electrodes to the subject. The AD8233 is an integrated signal conditioning block for electrocardiogram (ECG) and other biopotential measurement The AD8233 is available in a 2 mm 1.7 mm, 20-ball WLCSP applications. It is designed to extract, amplify, and filter small package and a 150 m thin die for height constrained applications. biopotential signals in the presence of noisy conditions, such as Performance is specified from 0C to 70C and is operational those created by motion or remote electrode placement. This from 40C to +85C. design allows an ultralow power analog-to-digital converter The AD8233 has several improvements over the AD8232, (ADC) or an embedded microcontroller to easily acquire the which are detailed in Table 1. output signal. Table 1. AD8232 vs. AD8233 Comparison The AD8233 implements a two-pole, high-pass filter for Parameter AD8232 AD8233 eliminating motion artifacts and the electrode half cell potential. Supply Current 170 A 50 A This filter is tightly coupled with the instrumentation amplifier Peak-to-Peak Voltage Noise 14 V p-p 8.5 V architecture to allow both large gain and high-pass filtering in a (f = 0.5 Hz to 40 Hz) single stage, thereby saving space and cost. Leads On or Off Detection Not included Included in Shutdown An uncommitted operational amplifier enables the AD8233 to Right Leg Drive Shutdown Not included Included create a three-pole, low-pass filter to remove additional noise. Package Size 4 mm 4 mm 2 mm 1.7 mm 0.75 mm 0.5 mm or 0.15 mm The user can select the frequency cutoff of all filters to suit different types of applications. Rev. D 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. Tel: 781.329.4700 20162020 Analog Devices, Inc. All rights reserved. No license is granted by implication or otherwise under any patent or patent rights of Analog Technical Support www.analog.com Devices. Trademarks and registered trademarks are the property of their respective owners. 13737-001AD8233 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Fast Restore Circuit .................................................................... 18 Applications ...................................................................................... 1 Leads On or Off Detection ........................................................ 19 General Description ......................................................................... 1 Standby Operation ..................................................................... 20 Functional Block Diagram .............................................................. 1 Input Protection ......................................................................... 20 Revision History ............................................................................... 2 Radio Frequency Interference .................................................. 21 Specifications .................................................................................... 3 Power Supply Regulation and Bypassing ................................ 21 Absolute Maximum Ratings ........................................................... 6 Input Referred Offsets ............................................................... 21 Thermal Resistance ...................................................................... 6 Layout Recommendations ........................................................ 21 ESD Caution.................................................................................. 6 Application Information ............................................................... 22 Pin Configurations and Function Descriptions ........................... 7 Eliminating Electrode Offsets ................................................... 22 Typical Performance Characteristics ............................................. 8 High-Pass Filtering .................................................................... 22 Instrumentation Amplifier Performance Characteristics ...... 8 Low-Pass Filtering and Gain .................................................... 24 Operational Amplifier Performance Characteristics ............ 11 Driven Electrode ........................................................................ 25 RLD Amplifier Performance Characteristics ......................... 14 Measuring Surface Electromyography (EMG) or Electroencephalography (EEG) ................................................ 25 Reference Buffer Performance Characteristics ...................... 15 Application Circuits ................................................................... 25 System Performance Characteristics ....................................... 16 Using AD5940, AD8232, and AD8233 for Bioimpedance and Theory of Operation ...................................................................... 17 Electrocardiogram (ECG) Measurements ................................. 29 Architecture Overview .............................................................. 17 Die Information .............................................................................. 30 Instrumentation Amplifier ....................................................... 17 Outline Dimensions ....................................................................... 31 Operational Amplifier ............................................................... 17 Ordering Guide .......................................................................... 32 RLD Amplifier ............................................................................ 17 Reference Buffer ......................................................................... 18 REVISION HISTORY 3/2020Rev. C to Rev. D Changes to Figure 28 ..................................................................... 13 Changes to Low-Pass Filtering and Gain Section and Table 7 ..... 24 Changes to Table 7 ......................................................................... 25 Added Measuring Surface Electromyography (EMG) or Electroencephalography (EEG) Section ...................................... 26 8/2019Rev. B to Rev. C Change to Table 4 ............................................................................. 6 Added Figure 77 ............................................................................. 28 Changes to Ordering Guide .......................................................... 32 Added Portable Heart Rate and Activity Monitor System Section .............................................................................................. 29 3/2019Rev. A to Rev. B Renamed Synchronized ECG and PPG Measurement Section to Changes to Table 7 ......................................................................... 24 Synchronous ECG and Photoplethysmography (PPG) Added Using AD5940, AD8232, and AD8233 for Measurement Using Transimpedance Amplifier (TIA) ADC Bioimpedance and Electrocardiogram (ECG) Measurements Mode Using the ADPD1080 Section ........................................... 29 Section .............................................................................................. 30 Changes to Synchronous ECG and Photoplethysmography Added Figure 79 Renumbered Sequentially .............................. 30 (PPG) Measurement Using Transimpedance Amplifier (TIA) ADC Mode Using the ADPD1080 Section ................................. 29 10/2018Rev. 0 to Rev. A Changes to Figure 79 Caption ...................................................... 29 Added 20-Pad Bare Die ...................................................... Universal Added Die Information Section, Figure 80, and Table 8, Changes to Features Section and General Description Section ...... 1 Renumbered Sequentially ............................................................. 30 Change to Table 1 ............................................................................. 1 Updated Outline Dimensions ...................................................... 31 Changes to Specifications Section and Table 2 ............................ 3 Changes to Ordering Guide .......................................................... 32 Change to Typical Performance Characteristics .......................... 9 Changes to Figure 13 ..................................................................... 10 8/2016Revision 0: Initial Version Rev. D Page 2 of 32