LMV321M5X National Semiconductor, LMV321M5X Datasheet - Page 16

• Manufacturer Part Number: LMV321M5X
• Description: IC,Operational Amplifier,SINGLE,BICMOS,TSOP,5PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LMV321M5X

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Notes
As shown in the waveforms in Figure 17 , the pulse width (T
is set by R
set by R
have different frequencies and pulse width by selecting dif-
ferent capacitor value and resistor values.
Figure 18 shows another pulse generator, with separate
charge and discharge paths. The capacitor is charged
through R1 and is discharged through R
Figure 19 is a squarewave generator with the same path for
charging and discharging the capacitor.
FIGURE 17. Waveforms of the Circuit in Figure 16
1
, C and V
2
, C and V
FIGURE 18. Pulse Generator
OL
OH
. This pulse generator can be made to
, and the time between pulses (T
(Continued)
2
.
DS100060-86
2
DS100060-77
) is
1
)
16
4.6 Current Source and Sink
The LMV321/358/324 can be used in feedback loops which
regulate the current in external PNP transistors to provide
current sources or in external NPN transistors to provide cur-
rent sinks.
4.6.1 Fixed Current Source
A multiple fixed current source is show in Figure 20 . A volt-
age (V
age divider (R
the voltage drop across R
the emitter current of transistor Q
current of Q
able out of the collector of Q
Large input resistors can be used to reduce current loss and
a Darlington connection can be used to reduce errors due to
the
The resistor, R
Q
2
either above or below the 1 mA reference value.
of Q
REF
1
= 2V) is established across resistor R
FIGURE 19. Squarewave Generator
.
FIGURE 20. Fixed Current Source
1
3
and Q
2
and R
, can be used to scale the collector current of
2
, essentially this same current is avail-
4
). Negative feedback is used to cause
1
to be equal to V
1
.
1
and if we neglect the base
REF
. This controls
3
DS100060-76
by the volt-
DS100060-80