ADPD2210ACPZ-RL

Overview

The ADPD2210ACPZ-RL is an ultralow noise, low power current amplifier designed for wearable photoplethysmography applications. It amplifies sensor signal currents by a factor of 24 while adding minimal noise, enabling the use of smaller photodiodes. The device features a typical noise floor of 80 fA/√Hz and operates with a supply current of 140 μA when active. It supports a single positive supply voltage ranging from 1.8 V to 5 V. The nominal linear output is 240 μA at 3.3 V, with a minimum linearity of 60 dB. The component is housed in a space-saving 2 mm × 2 mm LFCSP package.

Feature Summary

• Amplifies small sensor currents by a factor of 24 to achieve system sensitivity comparable to larger photodiodes.
• Features ultralow input-referred noise floor of 80 fA/√Hz for high signal-to-noise ratio performance.
• Includes a power-down pin that reduces supply current to approximately 100 nA during standby periods.
• Maintains near zero-bias voltage on the sensor input to minimize dark current and shot noise.

Applications

• Photoplethysmography
• Photodiode measurements
• Small current pulsed amperometry

Procurement Notes

Verify the specific ordering suffix RL against the manufacturer's official documentation to confirm packaging details. Ensure compatibility with the required operating temperature range of -40°C to +85°C. Confirm RoHS compliance status as indicated in the ordering guide. Cross-reference the part number with the latest datasheet revision A specifications to validate electrical parameters before integration.

Selection Notes

Select this component for designs requiring high sensitivity with minimal power consumption. The integrated current mirror simplifies circuit topology by reducing the need for external transimpedance amplifiers. Consider the 2 mm × 2 mm package size for space-constrained wearable devices. Evaluate the power-down recovery time requirements against the application's pulse mode timing constraints.

Part Context

The ADPD2210 is part of Analog Devices' portfolio of optical sensor interface solutions. It addresses the challenge of extracting small AC signals from large DC offsets in photoplethysmography systems. The device is optimized for battery-powered monitoring applications where ambient light rejection and low power are critical design factors.

Replacement Considerations

The ADPD2210ACPZ-R7 is a confirmed substitute part number listed in the manufacturer's ordering guide. Verify functional equivalence and pinout compatibility before substitution.

FAQ

How does the ADPD2210 handle ambient light interference?

The device is optimized for pulse mode applications, allowing the extraction of calibration signals during emitter off-periods to compensate for ambient light diffused throughout the tissue.

What is the function of the REF pin?

The REF pin provides a matched voltage reference for the current input, typically tied to the cathode of a photodiode to hold the sensor input within ±5 mV of the reference terminal.