Low Noise, Low Gain Drift, G = 2000, Instrumentation Amplifier Data Sheet AD8428-KGD FEATURES FUNCTIONAL BLOCK DIAGRAM +V FIL S Fixed gain of 2000 Access to internal nodes provides flexibility IN Low noise: 1.5 nV/Hz voltage noise 6k 6k 120k 3k High accuracy dc performance Gain drift: 10 ppm/C maximum OUT 30.15 Input offset voltage, average temperature coefficient: 1 V/C maximum 3k 6k 6k 120k Total gain error: 0.2% maximum REF +IN CMRR, dc to 60 Hz: 130 dB minimum AD8428-KGD Excellent ac specifications V +FIL 3 dB small signal bandwidth: 3.5 MHz S Slew rate: 40 V/s minimum Figure 1. Power supply operating range: 4 V to 18 V ESD protection: 5000 V (HBM) Temperature range for specified performance: 40C to +85C Operational up to 125C Known Good Die (KGD): these die are fully guaranteed to data sheet specifications. APPLICATIONS Sensor interface Medical instrumentation Patient monitoring GENERAL DESCRIPTION The AD8428-KGD is an ultralow noise instrumentation amplifier The AD8428-KGD uses a current feedback topology for the (in-amp) designed to accurately measure small, high speed signals. initial preamplifier gain stage of 200, followed by a difference amplifier stage of 10. This architecture results in a 3.5 MHz All gain setting resistors for the AD8428-KGD are internal to bandwidth at a gain of 2000. the device and are precisely matched. Care is taken in both the chip pinout and layout that results in excellent gain drift and The AD8428-KGD pin configuration allows access to internal quick settling to the final gain value after the device powers on. nodes between the first and second stages. This feature can be useful for modifying the frequency response between the two The high common-mode rejection ratio (CMRR) of the amplification stages, thereby preventing unwanted signals from AD8428-KGD prevents unwanted signals from corrupting the contaminating the output results. signal of interest. The pin configuration of the AD8428-KGD is designed to avoid parasitic capacitance mismatches that can The performance of the AD8428-KGD is specified from 40C degrade CMRR at high frequencies. to +85C and operational to 125C. The AD8428-KGD is one of the fastest in-amps available. The Additional application and technical information can be found circuit architecture is designed for high bandwidth at high gain. in the AD8428 data sheet. 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 2019 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 20263-001AD8428-KGD Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Absolute Maximum Ratings ............................................................5 Applications ....................................................................................... 1 ESD Caution...................................................................................5 Functional Block Diagram .............................................................. 1 Pin Configuration and Function Descriptions ..............................6 General Description ......................................................................... 1 Outline Dimensions ..........................................................................7 Revision History ............................................................................... 2 Die Specifications and Assembly Recommendations ...............7 Specif ications ..................................................................................... 3 Ordering Guide .............................................................................7 REVISION HISTORY 10/2019Revision 0: Initial Version Rev. 0 Page 2 of 7