May 1995
LMC6681 Single/LMC6682 Dual/LMC6684 Quad
Low Voltage, Rail-To-Rail Input and Output CMOS
Amplifier with Powerdown
General Description
Features
The LMC6681/2/4 is a high performance operational ampli-
fier which can operate over a wide range of supply voltages,
with guaranteed specifications at 1.8V, 2.2V, 3V, 5V, and
10V.
(Typical unless otherwise noted)
n Guaranteed Specs at 1.8V, 2.2V, 3V, 5V, 10V
n Rail-to-Rail Input Common-Mode Voltage Range
n Rail-to-Rail Output Swing
The LMC6681/2/4 provides an input common-mode voltage
range that exceeds both supplies. The rail-to-rail output
swing of the amplifier assures maximum dynamic signal
range. This rail-to-rail performance of the amplifier, com-
bined with its high open-loop voltage gain makes it unique
among CMOS rail-to-rail amplifiers. The LMC6681/2/4 is an
excellent choice for circuits where the common-mode volt-
age range is a concern.
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(within 10 mV of supply rail, VS 3V and RL 10 kΩ)
n Powerdown Mode IS OFF ≤ 1.5 µA/Amplifier
(Guaranteed at VS 1.8V, 2.2V, 3V, and 5V)
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n Ultra Low Input Current 80 fA
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n High Voltage Gain (VS 3V, RL 10 kΩ): 120 dB
n Unity Gain Bandwidth 1.2 MHz
Applications
n Battery Operated Circuits
n Sensor Amplifiers
The LMC6681/2/4 has a powerdown mode which can be
controlled externally. In this powerdown mode, the supply
current decreases from 700 µA per amplifier to less than 1
µA per amplifier. The LMC6684 has two powerdown options.
Each of the powerdown pins disables two amplifiers.
n Portable Communication Devices
n Medical Instrumentation
The LMC6681/2/4 has been designed specifically to improve
system performance in low voltage applications. The ampli-
fier’s 80 fA input current, 0.5 mV offset voltage, and 82 dB
CMRR maintain accuracy in battery-powered systems.
n Battery Monitoring Circuits
n Level Detectors, Sample-and-Hold Circuits
Connection Diagrams
8-Pin DIP/SO
14-Pin DIP/SO
DS012042-1
Top View
DS012042-2
Top View
16-Pin DIP/SO
DS012042-3
Top View
© 1999 National Semiconductor Corporation
DS012042
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