Ultralow Noise, Low Power Current Amplifier Data Sheet ADPD2210 FEATURES FUNCTIONAL BLOCK DIAGRAM Ultralow noise, low power current amplifier 80 fA/Hz (typical) noise floor VCC (2 V ) BE 2 140 A (typical) of supply current when active (E = 0 W/cm ) E BIAS POWER-DOWN PWDN LOGIC 100 nA (typical) of supply current in standby Flexible output configuration 10nA Optimized for pulsed systems OUT IN Nominal linear output: 240 A Space-saving 2 mm 2 mm LFCSP package 24 CURRENT MIRROR APPLICATIONS Photoplethysmography Photodiode measurements Figure 1. Small current pulsed amperometry Any application requiring the ultralow noise amplification of small currents GENERAL DESCRIPTION The ADPD2210 is a low noise current amplifier designed to The ADPD2210 is designed for applications where power allow the use of smaller photodiodes by amplifying sensor signal conservation is critical. The ADPD2210 uses very little power, currents by a factor of 24 while adding minimal noise. This typically 140 A with no input to 954 A at full scale. A power- amplification provides the system sensitivity of a large photodiode down pin places the ADPD2210 in standby when sensing is with the benefits of a smaller photodiode. A minimum linearity inactive. This mode adds critical time for battery-powered of 60 dB allows accurate extraction of very small time variant monitoring and can reduce battery costs in disposable applications signals on top of large dc or low frequency offsets. Using the ADPD2210 to provide sensor site amplification The ADPD2210 is optimized for pulse mode applications such reduces the effect of electromagnetic interference (EMI) in low as wrist worn heart rate monitoring (HRM) or finger worn level wired interfaces, providing improved signal-to-noise ratio pulse oximeter oxygen saturation (SpO2), where low power (SNR) and rejection of interferer signals from nearby equipment. consumption and rejection of ambient light is critical. In photodi- The combination of low power, high SNR, and EMI immunity ode applications, the ADPD2210 holds the sensor input to enables low power system solutions not possible with traditional within 5 mV (typical) of the reference terminal, providing small current sensors, such as photodiodes plus transimpedance near zero-bias voltage and allowing minimal dark current and amplifiers (TIAs). shot noise limited performance. Rev. A 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 2015 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. 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REF GND VCC 12286-101ADPD2210 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pulse Mode Operation ............................................................... 11 Applications ....................................................................................... 1 Applications Information .............................................................. 12 Functional Block Diagram .............................................................. 1 Powering the ADPD2210 .......................................................... 12 General Description ......................................................................... 1 Exposed Pad Connection .......................................................... 12 Revision History ............................................................................... 2 Power-Down ............................................................................... 12 Specif icat ions ..................................................................................... 3 Reference Ouput ......................................................................... 12 Absolute Maximum Ratings ............................................................ 4 Layout Considerations ............................................................... 12 Thermal Resistance ...................................................................... 4 Output Configuration ................................................................ 12 ESD Caution .................................................................................. 4 Accuracy in Clinical Applications ............................................ 12 Pin Configuration and Function Descriptions ............................. 5 3-Wire Voltage Configuration .................................................. 13 Typical Performance Characteristics ............................................. 6 3-Wire Current Mode Configuration ...................................... 13 Terminology .................................................................................... 10 Evaluation Board ............................................................................ 14 Theory of Operation ...................................................................... 11 Outline Dimensions ....................................................................... 15 O ver vie w ...................................................................................... 11 Ordering Guide .......................................................................... 15 Recommended Configuration .................................................. 11 Sensitivity and SNR .................................................................... 11 REVISION HISTORY 12/15Rev. 0 to Rev. A 10/15Revision 0: Initial Version Changes to Ordering Guide .......................................................... 15 Rev. A Page 2 of 15