ITT - Index of

ITT74124
UNIVERSAL PULSE GENERATOR
a. External timing capacitor. CT, may be connected
between pin 1 (11) positive and pin 2 (12).
With no external capacitance an output pulse
width of typically 25 ns is obtained with RT
= 1.5K,Q,+10Kil
b. To use the internal timing resistor (normally
7.2K.Q) connect pin 3 (13) to VCC (pin 14).
The pulse width or time delay is approximately
given byt = 5 X 103 CT'
c. To obtain variable resistor between pin 3 (13)
and V CC (pin 14). Add the value ofthe internal
resistor. 7.2K,Q to the external resistance
used, to obtain the RT value.
d. For accurate timing connect an external resistor
between pin 2 (12) and VCC (pin 14). Leave
pin 3 (13) open circuit.
Relationship for timing period, t = 0.695
CTRT where CT and RT are the timing components
values used.
Note: Timing periods of the order of one second
are obtained when using the maximum recommended
RT and CT component values.
1/ Delayed Pulse Mode a) Timing Period T1 » Timing Period T2 (inhibit = negative trigger" '0'1.
22
l2
LIl
n a IL-
U
bl Timing Period T1 « Timing Period T2.
n
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~LJ It--u
I!p U
~
Qj ~I n 2Z n __ ~rl~ ________________
02 ~l
02 a
2/ Oscillating Mode a) Timing Period T1 = Timing Period T2 (positive trigger = '0').
INHIBI~
l~'"l:-l--'--'
~--~~:r-~
_--..J1LJLJLj"-Ul l~:l:-l __ ~I-UU---U-U---
--LnJ~~
bl Timing Period Tt« Timing Period T2.
--1------
----'L ..--IL__.__----'
_____---.r- ~
LJ
Waveforms illustrating the function of the circuit in the delayed pulse and oscillating modes.
3-160