The AD8233 is an integrated signal conditioning block for ECG and other biopotential measurement applications. It is designed to extract, amplify, and filter small biopotential signals in the presence of noisy conditions, such as those created by motion or remote electrode placement. This design allows an ultralow power analog-to-digital converter (ADC) or an embedded microcontroller to easily acquire the output signal.
The AD8233 implements a two-pole high-pass filter for eliminating motion artifacts and the electrode half cell potential. This filter is tightly coupled with the instrumentation architecture of the amplifier to allow both large gain and high-pass filtering in a single stage, thereby saving space and cost.
An uncommitted operational amplifier enables the AD8233 to create a three-pole, low-pass filter to remove additional noise. The user can select the frequency cutoff of all filters to suit different types of applications.
To improve the common-mode rejection of the line frequencies in 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 the duration of the otherwise long settling tails of the high-pass filters. After an abrupt signal change that rails the amplifier (such as a leads off condition), the AD8233 automatically adjusts to a higher filter cutoff. This feature allows the AD8233 to recover quickly, and therefore, to take valid measurements soon after connecting the electrodes to the subject.
The AD8233 is available in a 2 mm × 1.7 mm, 20-ball WLCSP package. Performance is specified from 0°C to 70°C and is operational from −40°C to +85°C.
**Applications**
Fitness and activity heart rate monitors
Portable ECG
Wearable and remote health monitors
Gaming peripherals
Biopotential signal acquisition, such as EMG
### Features and Benefits
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
