CD54/74HC123, CD54/74HCT123,
CD74HC423, CD74HCT423
Data sheet acquired from Harris Semiconductor
SCHS142F
High-Speed CMOS Logic Dual Retriggerable
Monostable Multivibrators with Resets
September 1997 - Revised October 2003
Features
Ordering Information
• Overriding Reset Terminates Output Pulse
• Triggering From the Leading or Trailing Edge
• Q and Q Buffered Outputs
o
PART NUMBER
CD54HC123F3A
CD54HCT123F3A
CD74HC123E
TEMP. RANGE ( C)
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
PACKAGE
16 Ld CERDIP
16 Ld CERDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld SOP
[ /Title
(CD74
HC123
,
CD74
HCT12
3,
CD74
HC423
,
CD74
HCT42
3)
• Separate Resets
• Wide Range of Output-Pulse Widths
• Schmitt Trigger on Both A and B Inputs
• Fanout (Over Temperature Range)
CD74HC123M
CD74HC123MT
CD74HC123M96
CD74HC123NSR
CD74HC123PW
CD74HC123PWR
CD74HC123PWT
CD74HC423E
- Standard Outputs. . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
o
o
• Wide Operating Temperature Range . . . -55 C to 125 C
• Balanced Propagation Delay and Transition Times
16 Ld TSSOP
16 Ld TSSOP
16 Ld TSSOP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld SOP
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
- 2V to 6V Operation
CD74HC423M
- High Noise Immunity: N = 30%, N = 30%of V
IL IH
at
/Sub-
ject
(High
Speed
CC
CD74HC423MT
CD74HC423M96
CD74HC423NSR
CD74HCT123E
CD74HCT123M
CD74HCT123MT
CD74HCT123M96
CD74HCT423E
CD74HCT423MT
CD74HCT423M96
V
= 5V
CC
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
V = 0.8V (Max), V = 2V (Min)
IL IH
- CMOS Input Compatibility, I ≤ 1µA at V , V
OL OH
l
Description
The ’HC123, ’HCT123, CD74HC423 and CD74HCT423 are
dual monostable multivibrators with resets. They are all
retriggerable and differ only in that the 123 types can be
triggered by a negative to positive reset pulse; whereas the
423 types do not have this feature. An external resistor (R )
X
and an external capacitor (C ) control the timing and the
X
NOTE: When ordering, use the entire part number. The suffixes 96
and R denote tape and reel. The suffix T denotes a small-quantity
reel of 250.
accuracy for the circuit. Adjustment of Rx and C provides a
X
wide range of output pulse widths from the Q and Q
terminals. Pulse triggering on the A and B inputs occur at a
particular voltage level and is not related to the rise and fall
times of the trigger pulses.
Once triggered, the output pulse width may be extended by
retriggering inputs A and B. The output pulse can be
terminated by a LOW level on the Reset (R) pin. Trailing
edge triggering (A) and leading edge triggering (B) inputs
are provided for triggering from either edge of the input
pulse. If either Mono is not used each input on the unused
device (A, B, and R) must be terminated high or low.
The minimum value of external resistance, Rx is typically
5kΩ. The minimum value external capacitance, CX, is 0pF.
The calculation for the pulse width is t = 0.45 R C at
W
X X
V
= 5V.
CC
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © 2003, Texas Instruments Incorporated
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