MC54HC4538AJ

Manufacturer Part NumberMC54HC4538AJ
DescriptionDual precision monostable multivibrator
ManufacturerMotorola
MC54HC4538AJ datasheet
 
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PIN DESCRIPTIONS

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MC54/74HC4538A
INPUTS
A1, A2 (Pins 4, 12)
Positive–edge trigger inputs. A rising–edge signal on
either of these pins triggers the corresponding multivibrator
when there is a high level on the B1 or B2 input.
B1, B2 (Pins 5, 11)
Negative–edge trigger inputs. A falling–edge signal on
either of these pins triggers the corresponding multivibrator
when there is a low level on the A1 or A2 input.
Reset 1, Reset 2 (Pins 3, 13)
Reset inputs (active low). When a low level is applied to
one of these pins, the Q output of the corresponding multi-
vibrator is reset to a low level and the Q output is set to a high
level.
C X 1/R X 1 and C X 2/R X 2 (Pins 2 and 14)
External timing components. These pins are tied to the
common points of the external timing resistors and capaci-
RxCx
V CC
M1
V CC
2 k
M2
M3
A
B
RESET
POWER
ON
RESET
MOTOROLA

PIN DESCRIPTIONS

tors (see the Block Diagram). Polystyrene capacitors are
recommended for optimum pulse width control. Electrolytic
capacitors are not recommended due to high leakages
associated with these type capacitors.
GND (Pins 1 and 15)
External ground. The external timing capacitors discharge
to ground through these pins.
OUTPUTS
Q1, Q2 (Pins 6, 10)
Noninverted monostable outputs. These pins (normally
low) pulse high when the multivibrator is triggered at either
the A or the B input. The width of the pulse is determined by
the external timing components, R X and C X .
Q1, Q2 (Pins 7, 9)
Inverted monostable outputs. These pins (normally high)
pulse low when the multivibrator is triggered at either the A or
the B input. These outputs are the inverse of Q1 and Q2.
LOGIC DETAIL
(1/2 THE DEVICE)
UPPER
REFERENCE
OUTPUT
CIRCUIT
LATCH
+
V re , UPPER
LOWER
REFERENCE
CIRCUIT
+
V re , LOWER
TRIGGER CONTROL
CIRCUIT
C
Q
TRIGGER CONTROL
RESET CIRCUIT
CB
R
RESET LATCH
Figure 9.
3–8
Q
Q
High–Speed CMOS Logic Data
DL129 — Rev 6