NCV1455B ON Semiconductor, NCV1455B Datasheet - Page 8

• Manufacturer Part Number: NCV1455B
• Description: Timers
• Manufacturer: ON Semiconductor

Pulse Width Modulation
monostable mode of operation, the charge time of the
capacitor can be varied by changing the control voltage at
Pin 5. In this manner, the output pulse width can be
modulated by applying a modulating signal that controls the
threshold voltage.
If the timer is triggered with a continuous pulse train in the
Output
Clock
Input
9.1 k
1.0 mF
6
7
Figure 24. Pulse Width Modulator
R
2
L
8
MC1455
3
2
+V
CC
1
(5.0 V to 15 V)
4
4
MC1455
1
5
3
0.01 mF
Load
8
0.001 mF
27 k
5.0 mF
7
6
5
MC1455, MC1455B, NCV1455B
9.1 k
6
7
2
Modulation
Input
R
Figure 26. Sequential Timer
A
http://onsemi.com
MC1455
8
C
1
8
4
Test Sequences
sequential timing. An example is shown in Figure 26 where
the sequence is started by triggering the first timer which
runs for 10 ms. The output then switches low momentarily
and starts the second timer which runs for 50 ms and so forth.
5
3
Several timers can be connected to drive each other for
Load
0.01 mF
Figure 25. Pulse Width Modulation Waveforms
0.001 mF
27 k
5.0 mF
(R
18.2 k
A
= 10 kW, C = 0.02 mF, V
6
7
2
8
MC1455
t = 0.5 ms/cm
1
4
CC
= 15 V)
5
3
Load
0.01 mF
V
CC
(5.0 V to 15 V)