AD8476 Datasheet, PDF (1/24 Pages) Analog Devices – Low Power, Unity Gain, Fully

Data Sheet
Low Power, Unity Gain, Fully
Differential Amplifier and ADC Driver
AD8476
FEATURES
Very low power
330 μA supply current
Extremely low harmonic distortion
−126 HD2 at 10 kHz
−128 HD3 at 10 kHz
Fully differential or single-ended inputs/outputs
Differential output designed to drive precision ADCs
Drives switched capacitor and Σ-Δ ADCs
Rail-to-rail outputs
VOCM pin adjusts output common mode
Robust overvoltage up to 18 V beyond supplies
High performance
Suitable for driving 16-bit converter up to 250 kSPS
39 nV/√Hz output noise
1 ppm/°C gain drift maximum
200 μV maximum output offset
10 V/μs slew rate
6 MHz bandwidth
Single supply: 3 V to 18 V
Dual supplies: ±1.5 V to ±9 V
APPLICATIONS
ADC driver
Differential instrumentation amplifier building block
Single-ended-to-differential converter
Battery-powered instruments
GENERAL DESCRIPTION
The AD8476 is a very low power, fully differential precision
amplifier with integrated gain resistors for unity gain. It is an ideal
choice for driving low power, high performance ADCs as a
single-ended-to-differential or differential-to-differential
amplifier. It provides a precision gain of 1, common-mode level
shifting, low temperature drift, and rail-to-rail outputs for
maximum dynamic range.
The AD8476 also provides overvoltage protection from large
industrial input voltages up to ±23 V while operating on a dual 5 V
supply. Power dissipation on a single 5 V supply is only 1.5 mW.
The AD8476 works well with SAR, Σ-Δ, and pipeline converters.
The high current output stage of the part allows it to drive the
FUNCTIONAL BLOCK DIAGRAM
10kΩ
10kΩ
10kΩ
AD8476
10kΩ
NOTES
1. NC = NO CONNECT.
DO NOT CONNECT TO THIS PIN.
Figure 1. 8-Lead MSOP
INP 1
INP 2
INN 3
INN 4
10kΩ
10kΩ
10kΩ
AD8476
10kΩ
12 NC
11 –OUT
10 +OUT
9 VOCM
NOTES
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
Figure 2. 16-Lead LFCSP
switched capacitor front-end circuits of many ADCs with
minimal error.
Unlike many differential drivers on the market, the AD8476 is
a high precision amplifier. With 200 µV maximum output
offset, 39 nV/√Hz noise, and −102 dB THD + N at 10 kHz, the
AD8476 pairs well with low power, high accuracy converters.
Considering its low power consumption and high precision, the
slew-enhanced AD8476 has excellent speed, settling to 16-bit
precision for 250 kSPS acquisition times.
The AD8476 is available in space-saving 16-lead, 3 mm × 3 mm
LFCSP and 8-lead MSOP packages. It is fully specified over the
−40°C to +125°C temperature range.
Rev. B
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