Datasheet

LMV331-N, LMV339-N, LMV393-N
www.ti.com SNOS018G –AUGUST 1999–REVISED FEBRUARY 2013
By varying resistor R
1
, the time between pulses of the generator can be changed without changing the pulse
width. Similarly, by varying R
2
, the pulse width will be altered without affecting the time between pulses. Both
controls will change the frequency of the generator. The pulse width and time between pulses can be found from:
Figure 18. Pulse Generator
(16)
Solving these equations for t
1
and t
2
t
1
=R
4
C
1
ln2 (17)
t
2
=R
5
C
1
ln2 (18)
These terms will have a slight error due to the fact that V
max
is not exactly equal to 2/3 V
CC
but is actually
reduced by the diode drop to:
(19)
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