LMV393

Preliminary

LINEAR INTEGRATED CIRCUIT

UNISONIC TECHNOLOGIES CO., LTD

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www.unisonic.com.tw

QW-R104-004.c

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APPLI CAT I ON CI RCU I T S(Cont .)

Positive Peak Detector:

Positive peak detector is basically the comparator operated as a unit gain follower with a large holding capacitor

from the output to ground. Additional transistor is added to the output to provide a low impedance current source.

When the output of the comparator goes high, current is passed through the transistor to charge up the capacitor.

The only discharge path will be the 1M ohm resistor shunting C1 and any load that is connected to the output. The

decay time can be altered simply by changing the 1M

Ω resistor. The output should be used through a high

impedance follower to a avoid loading the output of the peak detector.

Negative Peak Detector:

For the negative detector, the output transistor of the comparator acts as a low impedance current sink. The only

discharge path will be the 1M

Ω resistor and any load impedance used. Decay time is changed by varying the 1MΩ

resistor.