Datasheet AD8476 (Analog Devices)

Low Power, Unity Gain, Ful y Differential Amplifier and ADC Driver Data Sheet AD8476 FEATURES FUNCTIONAL BLOCK DIAGRAM Very low power S UT 330 μA supply current INP –V NC –O 8 7 6 5 Extremely low harmonic distortion −126 HD2 at 10 kHz 10kΩ −128 HD3 at 10 kHz 10kΩ AD8476 Fully differential or single-ended inputs/outputs 10kΩ Differential output designed to drive precision ADCs 10kΩ Drives switched capacitor and Σ-Δ ADCs Rail-to-rail outputs 1 2 3 4 S VOCM pin adjusts output common mode INN UT +V CM O O + Robust overvoltage up to 18 V beyond supplies V NOTES
001
High performance 1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
10195-
Suitable for driving 16-bit converter up to 250 kSPS
Figure 1. 8-Lead MSOP
39 nV/√Hz output noise S S S S 1 ppm/°C gain drift maximum –V –V –V –V 200 μV maximum output offset 16 15 14 13 10 V/μs slew rate 6 MHz bandwidth INP 1 12 NC Single supply: 3 V to 18 V 10kΩ 10kΩ Dual supplies: ±1.5 V to ±9 V INP 2 11 –OUT 10kΩ AD8476 INN 3 10 +OUT APPLICATIONS 10kΩ ADC driver INN 4 9 VOCM Differential instrumentation amplifier building block Single-ended-to-differential converter 5 6 7 8 Battery-powered instruments S S S S +V +V +V +V
002
NOTES 1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
10195- Figure 2. 16-Lead LFCSP
GENERAL DESCRIPTION
The AD8476 is a very low power, fully differential precision switched capacitor front-end circuits of many ADCs with amplifier with integrated gain resistors for unity gain. It is an ideal minimal error. choice for driving low power, high performance ADCs as a Unlike many differential drivers on the market, the AD8476 is single-ended-to-differential or differential-to-differential a high precision amplifier. With 200 µV maximum output amplifier. It provides a precision gain of 1, common-mode level offset, 39 nV/√Hz noise, and −102 dB THD + N at 10 kHz, the shifting, low temperature drift, and rail-to-rail outputs for AD8476 pairs well with low power, high accuracy converters. maximum dynamic range. Considering its low power consumption and high precision, the The AD8476 also provides overvoltage protection from large slew-enhanced AD8476 has excellent speed, settling to 16-bit industrial input voltages up to ±23 V while operating on a dual 5 V precision for 250 kSPS acquisition times. supply. Power dissipation on a single 5 V supply is only 1.5 mW. The AD8476 is available in space-saving 16-lead, 3 mm × 3 mm The AD8476 works well with SAR, Σ-Δ, and pipeline converters. LFCSP and 8-lead MSOP packages. It is fully specified over the The high current output stage of the part al ows it to drive the −40°C to +125°C temperature range.
Rev. B 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 rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 www.analog.com Trademarks and registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2011–2012 Analog Devices, Inc. All rights reserved.
Document Outline Features Applications Functional Block Diagram General Description Revision History Specifications Absolute Maximum Ratings Thermal Resistance Maximum Power Dissipation ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Terminology Theory of Operation Overview Circuit Information Output Common-Mode Voltage (VOCM) DC Precision Input Voltage Range Driving the AD8476 Power Supplies Applications Information Typical Configuration Single-Ended-to-Differential Conversion Setting the Output Common-Mode Voltage Low Power ADC Driving Outline Dimensions Ordering Guide