LMV921 datasheet(21/42 Pages) NSC

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2-15

LMV921 Qualification Package

2.0 DEVICE INFORMATION

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 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

I should be

large enough not to load the LMV921.

DS100979-C3

DS100979-C2

DS100979-C4

FIGURE 5. Half-Wave Rectifier with Rail-To-Ground Output Swing Referenced to Ground

DS100979-C0

DS100979-B9

DS100979-C1

FIGURE 6. Half-Wave Rectifier with Negative-Going Output Referenced to V

LMV921 数据表(PDF) 21 Page - National Semiconductor (TI)