LMC6492 Datasheet, PDF (14/18 Pages) National Semiconductor (TI) – CMOS Rail-to-Rail Input and Output Operational Amplifier

Application Circuits (Continued)
High Input Z, DC Differential Amplifier
Rail-to-Rail Single Supply Low Pass Filter
DS012049-22
DS012049-19
For
(CMRR depends on this resistor ratio match)
As shown: V_O = 2(V₂ − V₁)
Photo Voltaic-Cell Amplifier
This low-pass filter circuit can be used as an anti-aliasing fil-
ter with the same supply as the A/D converter. Filter designs
can also take advantage of the LMC6492/4 ultra-low input
current. The ultra-low input current yields negligible offset er-
ror even when large value resistors are used. This in turn al-
lows the use of smaller valued capacitors which take less
board space and cost less.
Low Voltage Peak Detector with Rail-to-Rail Peak
Capture Range
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Instrumentation Amplifier
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Dielectric absorption and leakage is minimized by using a
polystyrene or polypropylene hold capacitor. The droop rate
is primarily determined by the value of C_H and diode leakage
current. Select low-leakage current diodes to minimize
drooping.
Pressure Sensor
If R1 = R5, R3 = R6, and R4 = R7; then
∴A_V ≈ 100 for circuit shown (R₂ = 9.3k).
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DS012049-21
R_f = Rx
R_f >> R1, R2, R3, and R4
DS012049-24
In a manifold absolute pressure sensor application, a strain
gauge is mounted on the intake manifold in the engine unit.
Manifold pressure causes the sensing resistors, R1, R2, R3
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