RESET OPERATION

CD is normally high. If CD is low, the trigger is not

effective because Q output goes low and trigger

control flip-flop is reset.

Also transistor Op is turned on and Cx is charged

IC becomes waiting state both in operating and non

operating state.

FUNCTIONAL DESCRIPTION (continued)

TRUTH TABLE

INPUTS

OUTPUTS

NOTE

AB

CD

Q

Q

H

H

OUTPUT ENABLE

X

L

H

L

H

INHIBIT

H

X

H

L

H

INHIBIT

L

H

OUTPUT ENABLE

X

X

L

L

H

INHIBIT

INPUT AND OUTPUT EQUIVALENT CIRCUIT

PIN DESCRIPTION

PIN No

SYMBOL

NAME AND FUNCTION

1, 15

1T1, 2T1

External Capacitor

Connections

2, 14

1T2, 2T2

External Resistor/Capacitor

Connections

3, 13

1CD, 2CD

Direct Reset Inputs (Active

LOW)

4, 12

1A, 2A

Trigger Inputs (LOW to

HIGH, Edge-Triggered)

5, 11

1B, 2B

Trigger Inputs (HIGH to

LOW, Edge-Triggered)

6, 10

Q1, Q2

Pulse Outputs

7, 9

Q1, Q2

Complementary Pulse Outputs

8

GND

Ground (0V)

16

Positive Supply Voltage

IEC LOGIC SYMBOL

M54/M74HC4538

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