LMV7275MG National Semiconductor, LMV7275MG Datasheet - Page 14

• Manufacturer Part Number: LMV7275MG
• Description: IC,VOLT COMPARATOR,SINGLE,BICMOS,TSSOP,5PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LMV7275MG

• Rohs Compliant: NO

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Typical Applications
NEGATIVE PEAK DETECTOR
For the negative detector, the output transistor of the com-
parator acts as a low impedance current sink. Since there is
no pull-up resistor, the only discharge path will be the 1MΩ
resistor and any load impedance used. Decay time is
changed by varying the 1MΩ resistor.
SQUARE WAVE GENERATOR
A typical application for a comparator is as a square wave
oscillator. The circuit below generates a square wave whose
period is set by the RC time constant of the capacitor C
resistor R
signal propagation delay of the comparator, and by the ca-
pacitive loading at the output, which limits the output slew
rate.
4
. The maximum frequency is limited by the large
FIGURE 9. Negative Peak Detector
(Continued)
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1
and
14
To analyze the circuit, consider it when the output is high.
That implies that the inverted input (V
non-inverting input (V
through R
non-inverting input. The value of V
If R
At this point the comparator switches pulling down the output
to the negative rail. The value of V
If R
The capacitor C
age V
comparator switches again, bringing it back to the initial
stage. The time period is equal to twice the time it takes to
discharge C
R
F = 1/(2·R
4
C
1
1
1
.ln2. Hence the formula for the frequency is:
= R
= R
C
decreases till it is equal to V
2
2
4,
4
= R
= R
FIGURE 10. Squarewave Oscillator
·C
and the voltage V
1
1
3
3
·ln2)
from 2V
then V
then V
1
now discharges through R
A
). This causes the C
A1
A2
CC
= 2V
= V
/3 to V
C
CC
CC
increases till it is equal to the
/3
/3
CC
A
A
at this point is
at this point is
/3, which is given by
A2
C
, at which point the
) is lower than the
1
4
to get charged
, and the volt-
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