原标题：ADI AD8233心电图(ECG)信号调理模块解决方案

　　ADI公司的AD8233是适用于心电图(ECG)和其他生物电势测量应用的集成信号调理模块,低静态电源电流为50 μA(典型值),直流至60 Hz的共模抑制比为80 dB,具有可调增益的三极可调低通滤波器,关断功能的集成右腿驱动 (RLD)放大器,高信号增益(G = 100)以及隔直流功能,工作电压1.7V-3.5V,主要用在健身和活动是心脏速率监视器,手持心电图(ECG),穿戴和遥控健康监测器,游戏机外设和生物信号采集如EMG等.本文介绍了AD8233主要特性,功能框图,简化电路图和应用电路,以及评估板AD8233CB-EBZ主要特性,框图,电路图,材料清单和PCB设计图.

　　The AD8233 is an integrated signal conditioning block for ECGand other biopotential measurement applications. It is designedto extract, amplify, and filter small biopotential signals in thepresence of noisy conditions, such as those created by motion orremote electrode placement. This design allows an ultralowpower analog-to-digital converter (ADC) or an embeddedmicrocontroller to easily acquire the output signal.

　　The AD8233 implements a two-pole high-pass filter foreliminating motion artifacts and the electrode half cell potential.

　　This filter is tightly coupled with the instrumentation architectureof the amplifier to allow both large gain and high-passfiltering in a single stage, thereby saving space and cost.An uncommitted operational amplifier enables the AD8233 tocreate a three-pole, low-pass filter to remove additional noise.

　　The user can select the frequency cutoff of all filters to suitdifferent types of applications.To improve the common-mode rejection of the line frequenciesin the system and other undesired interferences, the AD8233 includes an amplifier for driven lead applications, RLD.

　　The AD8233 includes a fast restore function that reduces theduration of the otherwise long settling tails of the high-passfilters. After an abrupt signal change that rails the amplifier(such as a leads off condition), the AD8233 automaticallyadjusts to a higher filter cutoff. This feature allows the AD8233to recover quickly, and therefore, to take valid measurementssoon after connecting the electrodes to the subject.

　　The AD8233 is available in a 2 mm × 1.7 mm, 20-ball WLCSPpackage. Performance is specified from 0℃ to 70℃ and isoperational from −40℃ to +85℃.

　　AD8233主要特性:

　　Fully integrated, single-lead electrocardiogram (ECG) front end

　　Low quiescent supply current: 50 μA (typical)

　　Leads on/off detection while in shutdown (<1 μA)

　　Common-mode rejection ratio: 80 dB (dc to 60 Hz)

　　2 or 3 electrode configurations

　　High signal gain (G = 100) with dc blocking capabilities

　　2-pole adjustable high-pass filter

　　Accepts up to ±300 mV of half cell potential

　　Fast restore feature improves filter settling

　　Uncommitted op amp

　　3-pole adjustable low-pass filter with adjustable gain

　　Integrated right leg drive (RLD) amplifier with shutdown

　　Single-supply operation: 1.7 V to 3.5 V

　　Integrated reference buffer generates virtual ground

　　Rail-to-rail output

　　Internal RFI filter

　　8 kV human body model (HBM) ESD rating

　　Shutdown pin

　　2 mm × 1.7 mm WLCSP

　　AD8233应用:

　　Fitness and activity heart rate monitors

　　Portable ECG

　　Wearable and remote health monitors

　　Gaming peripherals

　　Biopotential signal acquisition, such as EMG

　　图1.AD8233功能框图

　　图2.AD8233简化电路图

　　图3.AD8233接近心脏的心电图电路图

　　图4.AD8233手上的心电图电路图

　　图5.AD8233Holter监测电路图

　　图6.AD8233同步ECG和PPG测量电路图

　　评估板AD8233CB-EBZ

　　The AD8233CB-EBZ evaluation board contains an AD8233 heart rate monitor (HRM) front end conveniently mounted with the necessary components for initial evaluation in fitness applications. Inputs, outputs, supplies, and leads off detection terminals are routed to test pins to simplify connectivity. Switches and jumpers are available for setting the input bias voltage, shutdown (SDN), right leg drive shutdown (RLD SDN), fast restore (FR), and ac/dc leads off detection mode.

　　The AD8233CB-EBZ evaluation board is a 4-layer board with components mounted on the primary side only. Rubber feet are available on the secondary side for mechanical stability. The layout diagrams are provided as a visual aid and reference design. The printed circuit board (PCB) is designed following standard practices to ensure signal integrity and reduce manufacturing costs. For best WLCSP layout practices, refer to AN-617.

　　Full details about the AD8233 are available in the AD8233 data sheet, which is available from Analog Devices, Inc., and should be consulted in conjunction with this user guide when using this evaluation board.

　　评估板AD8233CB-EBZ主要特性:

　　Ready to use HRM front end

　　Operates in two-electrode or three-electrode configurations

　　Directly interfaces to data acquisition and analog-to-digital converters (ADCs)

　　Easy mode selection with switches

　　Allows various circuit configurations

　　3.5 mm electrode jack

　　图7.评估板AD8233CB-EBZ外形图

　　评估板AD8233CB-EBZ材料清单:

　　详情请见:

AD8233CB-EBZ-UG-1016.pdf

AD8233.pdf