Integrated Circuits

4538
Dual retriggerable precision monostable multivibrator with reset
PDF datasheet
       
1CEXT 1  • 16 Vcc
1REXT/CEXT 2 15 2CEXT
1CD 3 14 2REXT/CEXT
1B 4 13 2CD
1A 5 12 2B
1Q 6 11 2A
1Q 7 10 2Q
GND 8 9 2Q
       
Pin Symbol Description
1 1CEXT external capacitor connection (connect to capacitor and ground)
2 1REXT/CEXT external capacitor/resistor connection
3 1CD clear direct input (active low)
4 1B input (low-to-high triggered)
5 1A input (high-to-low triggered)
6 1Q output
7 1Q complementary output
8 GND ground
9 2Q complementary output
10 2Q output
11 2A input (high-to-low triggered)
12 2B input (low-to-high triggered)
13 2CD clear direct input (active low)
14 2REXT/CEXT external capacitor/resistor connection
15 2CEXT external capacitor connection (connect to capacitor and ground)
16 Vcc supply voltage


Specifications
(typical values under recommended operating conditions, unless specified)
Parameter Value Unit
External timing resistor REXT 5 (min) k Ω
External timing capacitor CEXT 2000 (min) pF
Pulse width variation, Vcc = 5V ±0.2 %

Notes
  • Connect a timing capacitor CEXT between nCEXT and nREXT/CEXT.
  • Connect a resistor REXT between nREXT/CEXT and Vcc.
  • A high-to-low transition on nA when nB is low causes a pulse on nQ and nQ .
  • A low-to-high transition on nB when nA is high causes a pulse on nQ and nQ .
  • Setting nCD low inhibits pulses.
  • Output pulse width = REXT ×CEXT .
  • (74HC4538) Output pulse width = 0.7 ×REXT ×CEXT .

Note
Data is maintained by an independent source and accuracy is not guaranteed. Check with the manufacturer's datasheet for up-to-date information.

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