lmv924 National Semiconductor Corporation, lmv924 Datasheet - Page 17

• Manufacturer Part Number: lmv924
• Description: 1.8v, 1mhz, Low Power Operational Amplifiers With Rail-to-rail Input And Output
• Manufacturer: National Semiconductor Corporation

Typical Applications
1.0 Half-wave Rectifier with Rail-To-Ground Output
Swing
Since the LMV921 input common mode range includes both
positive and negative supply rails and the output can also
swing to either supply, achieving half-wave rectifier functions
in either direction is an easy task. All that is needed are two
external resistors; there is no need for diodes or matched re-
sistors. The half wave rectifier can have either positive or
negative going outputs, depending on the way the circuit is
arranged.
FIGURE 5. Half-Wave Rectifier with Rail-To-Ground Output Swing Referenced to Ground
FIGURE 6. Half-Wave Rectifier with Negative-Going Output Referenced to V
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In Figure 5 the circuit is referenced to ground, while in Figure
6 the circuit is biased to the positive supply. These configura-
tions implement the half wave rectifier since the LMV921 can
not respond to one-half of the incoming waveform. It can not
respond to one-half of the incoming because the amplifier
can not swing the output beyond either rail therefore the out-
put disengages during this half cycle. During the other half
cycle, however, the amplifier achieves a half wave that can
have a peak equal to the total supply voltage. R
large enough not to load the LMV921.
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CC
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I
should be