LMV331-N, LMV339-N, LMV393-N

SNOS018H – AUGUST 1999 – REVISED DECEMBER 2014

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Typical Applications (continued)

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(18)

reduced by the diode drop to:

(19)

(20)

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8.2.4 Positive Peak Detector

Figure 25. 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 1-M

Ω resistor shunting C1 and any load that is connected to the

output. The decay time can be altered simply by changing the 1-M

Ω resistor. The output should be used through

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

8.2.5 Negative Peak Detector

Figure 26. 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 1-M

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

M

Ω resistor.

20

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