Dual Retriggerable Resettable Multivibrator
(Previous ADE-205-365 (Z))
Each half of the HD74AC123A features retriggerable capability, complementary dc level triggering and overriding
Direct Clear. When a circuit is in the quasi-stable (delay) state, another trigger applied to the inputs (per the Truth
Table) will cause the delay period to start again, without disturbing the outputs. By repeating this process, the output
pulse period (Q High, Q Low) can be made as long as desired. Alternatively, a delay period can be terminated at any
time by a Low signal on CD, which also inhibits triggering. An internal connection from CD to the input gate makes it
possible to trigger the circuit by a positive-going signal on CD, as shown in the Truth Table. For timing capacitor values
greater than 1000 pF, the output pulse width is defined as follows.
Where tw is in ns, RX is in kΩ and CX is in pF.
tw = RXCX
• Outputs Source/Sink 24 mA
• Ordering Information
Package Type Package Code Package Abbreviation Taping Abbreviation (Quantity)
HD74AC123AP DIP-16 pin
DP-16E, -16FV P
HD74AC123AFPEL SOP-16 pin (JEITA) FP-16DAV
EL (2,000 pcs/reel)
HD74AC123ARPEL SOP-16 pin (JEDEC) FP-16DNV
EL (2,500 pcs/reel)
Notes: 1. Please consult the sales office for the above package availability.
2. The packages with lead-free pins are distinguished from the conventional products by adding V at the end of
the package code.
Rev.2.00, Jul.16.2004, page 1 of 6