for offset voltage, CMRR and gain. Low cost and low power

consumption are the main advantages of this two op-amp

circuit.

Higher frequency and larger common-mode range applica-

tions are best facilitated by a three op-amp instrumentation

amplifier.

11.0 Spice Macromodel

A spice macromodel is available for the LMC6484. This

model includes accurate simulation of:

•

input common-mode voltage range

•

frequency and transient response

•

GBW dependence on loading conditions

•

quiescent and dynamic supply current

•

output swing dependence on loading conditions

and many more characteristics as listed on the macromodel

disk.

Contact your local National Semiconductor sales office to

obtain an operational amplifier spice model library disk.

Typical Single-Supply Applications

The circuit in

Figure 17 use a single supply to half wave rec-

tify a sinusoid centered about ground. R

the amplifier caused by the input voltage exceeding the sup-

ply voltage. Full wave rectification is provided by the circuit in

Figure 19.

DS011714-30

FIGURE 16. Low-Power Two-Op-Amp Instrumentation Amplifier

DS011714-31

FIGURE 17. Half-Wave Rectifier with

Input Current Protection (RI)

DS011714-32

FIGURE 18. Half-Wave Rectifier Waveform

DS011714-33

FIGURE 19. Full Wave Rectifier

with Input Current Protection (R

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