zsct1555 Zetex Semiconductors plc., zsct1555 Datasheet - Page 8

• Manufacturer Part Number: zsct1555
• Description: Precision Single Cell Timer
• Manufacturer: Zetex Semiconductors plc.

Issue 3 - July 2006
© Zetex Semiconductors plc 2006
Figure 5 shows the monostable mode used as
a pulse width modulator. Here the trigger pin
is supplied with a continuous pulse train, the
resulting output pulse width is modulated by
a signal applied to the control pin.
Figure 6 shows typical waveform examples.
Figure 5
Figure 6
ZSCT1555
Astable operation
The configuration of Figure 7 produces a free
running multivibrator circuit whose frequency
is independent of supply voltage. The ratio of
resistors RA and RB precisely sets the circuit
duty cycle. The capacitor is charged and
discharged between thresholds at 0.2V
0.8V
(d) can be calculated using the following
equations:-
f = 0.62/(RA + 2RB)C
d = RB /(RA + 2RB)
Figure 8 shows the waveforms generated in
this mode of operation.
Figure 7
Figure 8
CC
. Oscillation frequency (f) and duty cycle
T
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CC
and