Bidirectional, Zero Drift, Current Sense Amplifier Data Sheet AD8418 FEATURES GENERAL DESCRIPTION Typical 0.1 V/C offset drift The AD8418 is a high voltage, high resolution current shunt Maximum 400 V voltage offset over full temperature range amplifier. It features an initial gain of 20 V/V, with a maximum 2.7 V to 5.5 V power supply operating range 0.15% gain error over the entire temperature range. The Electromagnetic interference (EMI) filters Included buffered output voltage directly interfaces with any typical High common-mode input voltage range converter. The AD8418 offers excellent input common-mode 2 V to +70 V operating rejection from 2 V to +70 V. The AD8418 performs bidirectional 4 V to +85 V survival current measurements across a shunt resistor in a variety of Initial gain = 20 V/V automotive and industrial applications, including motor Wide operating temperature range: 40C to +125C control, battery management, and solenoid control. Bidirectional operation Available in 8-lead SOIC and 8-lead MSOP The AD8418 offers breakthrough performance throughout the Common-mode rejection ratio (CMRR): 86 dB, dc to 10 kHz 40C to +125C temperature range. It features a zero drift core, Qualified for automotive applications which leads to a typical offset drift of 0.1 V/C throughout the operating temperature range and the common-mode voltage range. The AD8418 is fully qualified for automotive applications APPLICATIONS and includes EMI filters and patented circuitry to enable output High-side current sensing in accuracy with pulse-width modulation (PWM) type input Motor controls common-mode voltages. The typical input offset voltage is Solenoid controls 200 V. The AD8418 is offered in 8-lead MSOP and SOIC Power management packages. Low-side current sensing Diagnostic protection Table 1. Related Devices Part No. Description AD8205 Current sense amplifier, gain = 50 AD8206 Current sense amplifier, gain = 20 AD8207 High accuracy current sense amplifier, gain = 20 AD8210 High speed current sense amplifier, gain = 20 FUNCTIONAL BLOCK DIAGRAM V = 2V TO +70V V = 2.7V TO 5.5V CM S 70V V V 1 S REF V OUT V V S CM AD8418 +IN EMI + FILTER I SHUNT 0V OUT G = 20 R SHUNT V /2 S IN EMI FILTER 50A I SHUNT 0V GND V 2 REF 50A Figure 1. Rev. 0 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 2013 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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Technical Support www.analog.com 11546-001AD8418 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Unidirectional Operation .......................................................... 11 Applications ....................................................................................... 1 Bidirectional Operation ............................................................. 11 General Description ......................................................................... 1 External Referenced Output ..................................................... 12 Functional Block Diagram .............................................................. 1 Splitting the Supply .................................................................... 12 Revision History ............................................................................... 2 Splitting an External Reference ................................................ 12 Specifications ..................................................................................... 3 Applications Information .............................................................. 13 Absolute Maximum Ratings ............................................................ 4 Motor Control ............................................................................. 13 ESD Caution .................................................................................. 4 Solenoid Control ........................................................................ 14 Pin Configuration and Function Descriptions ............................. 5 Outline Dimensions ....................................................................... 15 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 16 Theory of Operation ...................................................................... 10 Automotive Products ................................................................. 16 Output Offset Adjustment ............................................................. 11 REVISION HISTORY 9/13Revision 0: Initial Version Rev. 0 Page 2 of 16