LMV7271_08 NSC [National Semiconductor], LMV7271_08 Datasheet - Page 13

• Manufacturer Part Number: LMV7271_08
• Description: Single & Dual, 1.8V Low Power Comparators with Rail-to-Rail Input
• Manufacturer: NSC [National Semiconductor]

Typical Applications
UNIVERSAL LOGIC LEVEL SHIFTER
The output of LMV7275 is an unconnected drain of an NMOS
device, which can be pulled up, through a resistor, to any de-
sired output level within the permitted power supply range.
Hence, the following simple circuit works as a universal logic
level shifter, pulling up the signal to the desired level.
POSITIVE PEAK DETECTOR
A positive peak detect circuit is basically a comparator oper-
ated in a unity gain follower configuration, with a capacitor as
a load to maintain the highest voltage. A diode is added at the
output to prevent the capacitor from discharging through the
pull-up resistor, and a 1MΩ resistor added in parallel to the
capacitor to provide a high impedance discharge path. When
the input V
follows it, thus charging the capacitor. When it decreases, the
cap discharges through the 1MΩ resistor. The decay time can
be modified by changing the resistor. The output should be
accessed through a follower circuit to prevent loading.
IN
FIGURE 7. Positive Peak Detector
increases, the inverting input of the comparator
FIGURE 6. Logic Level Shifter
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OR'ING THE OUTPUT
Since the output is an unconnected NMOS drain, many drains
can be tied together, pulled up to V
provide an output OR'ing function. If any of the comparator
outputs is pulled low the output V
FIGURE 8. OR’ing the Outputs
O
goes down.
DD
by a single resistor to
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