40 A Micropower Instrumentation Amplifier in WLCSP Package Data Sheet AD8235 FEATURES CONNECTION DIAGRAM R Low power G +V V S S RG RG B3 C3 A1 D1 40 A maximum supply current 6 nA shutdown current ESD ESD PROTECTION PROTECTION Low input currents A2 SDN 50 pA input bias current ESD REF C1 PROTECTION 25 pA input offset current 210k 52.5k 52.5k 210k High Common Mode Rejection Ratio (CMRR) OP AMP 110 dB CMRR , G = 100 ESD A B1 V NC B2 OP AMP OUT PROTECTION B Space saving WLCSP package D2 NC ESD ESD PROTECTION PROTECTION Zero input crossover distortion AD8235 Versatile A3 D3 Rail-to-rail input and output +IN IN Shutdown Figure 1. Gain set with single resistor (G = 5 to 200) PIN CONFIGURATION AD8236: SOIC package version of AD8235 BALL A1 INDICATOR APPLICATIONS 1 23 Medical instrumentation +V SDN IN S Low-side current sense A Portable electronics V OUT RG NC B GENERAL DESCRIPTION REF RG The AD8235 is the smallest and lowest power instrumentation C amplifier in the industry. It is available in a 1.5 mm 2.2 mm V NC +IN S wafer level chip scale package (WLCSP). The AD8235 draws D a maximum quiescent current of 40 A. In addition, it draws a TOP VIEW maximum 500 nA of current during shutdown mode, making (BALL SIDE DOWN) Not to Scale it an excellent instrumentation amplifier for battery powered, NC = NO CONNECT portable applications. Figure 2. 11-Ball WLCSP (CB-11-1) The AD8235 can operate on supply voltages as low as 1.8 V. The 5.0 input stage allows for wide rail-to-rail input voltage range without 4.5 the crossover distortion, common in other designs. The rail-to- G = 5 4.0 rail output enables easy interfacing to ADCs. V = 5V S V = 2.5V 3.5 REF The AD8235 is an excellent choice for signal conditioning. Its 3.0 low input bias current of 50 pA and high CMRR of 110 dB 2.5 (G = 100) offer tremendous value for its size and low power. 2.0 It is specified over the extended industrial temperature range of 1.5 40C to 125C. G = 5 V = 1.8V 1.0 S V = 0.9V REF 0.5 0 0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 OUTPUT VOLTAGE (V) Figure 3. Wide Common-Mode Voltage Range vs. Output Voltage 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 20092016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. INPUT COMMON-MODE VOLTAGE (V) 08211-004 08211-002 08211-001AD8235 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Shutdown Feature ....................................................................... 15 Applications ....................................................................................... 1 Layout Recommendations ........................................................ 15 General Description ......................................................................... 1 Reference Terminal .................................................................... 16 Connection Diagram ....................................................................... 1 Power Supply Regulation and Bypassing ................................ 16 Pin Configuration ............................................................................. 1 Input Bias Current Return Path ............................................... 17 Revision History ............................................................................... 2 Input Protection ......................................................................... 17 Specif icat ions ..................................................................................... 3 RF Interference ........................................................................... 17 Absolute Maximum Ratings ............................................................ 7 Common-Mode Input Voltage Range ..................................... 18 Thermal Resistance ...................................................................... 7 Applications Information .............................................................. 19 Pin Configuration and Function Descriptions ............................. 8 AC-Coupled Instrumentation Amplifier ................................ 19 Typical Performance Characteristics ............................................. 9 Low Power Heart Rate Monitor ............................................... 19 Theory of Operation ...................................................................... 14 Outline Dimensions ....................................................................... 20 Basic Operation .......................................................................... 14 Ordering Guide .......................................................................... 20 Gain Selection ............................................................................. 14 REVISION HISTORY 9/2016Rev. 0 to Rev. A Updated Outline Dimensions ....................................................... 20 8/2009Revision 0: Initial Version Rev. A Page 2 of 20