HD74HC423A

HD74HC423A Dual Retriggerable Monostable Multivibrators Description This multivibrator features output-pulse-duration control by two methods. The basic pulse duration is programmed by selection of external resistance and capacitance values. Once triggered, the basic pulse duration may be extended by retriggering the gated low-level-active (A) or high-level-active (B) inputs, or be reduced by use of the overriding clear. The B input is a Schmitt trigger enabling jitter-free triggering from input signals with slow transition rates. Features High Speed Operation High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current Function Table Inputs Clear L X X H H A X H X L H B X X L Output Q L L L Q H H H HD74HC423A Pin Arrangement 1A 1B 1CLR 1Q 2Q 2Cext 2Rext/Cect GND 1 2 3 4 5 6 7 8 CLR CLR 16 15 14 13 12 11 10 9 VCC 1Rext/Cext 1Cext 1Q 2Q 2CLR 2B 2A Logic diagram Rext Cext VCC VH VL OUT Q Q A B CLR CK CK CLR To Another Transceiver 2 HD74HC423A DC Characteristics SymItem Input voltage bol VIH VCC Ta = 25°C (V) Min Ta = –40 to +85°C Typ Max Min Max Unit Test Conditions — — — — 0.5 1.5 — V 2.0 1.5 4.5 3.15 — 6.0 4.2 VIL 2.0 — 4.5 — 6.0 — Output voltage VOH 2.0 1.9 4.5 4.4 6.0 5.9 — — — — 2.0 4.5 6.0 3.15 — 4.2 — — 0.5 1.35 1.8 — — — IOH = –4 mA IOH = –5.2 mA V Vin = VIH or VIL IOL = 20 µA V Vin = VIH or VIL IOH = –20 µA V 1.35 — 1.8 — — — — — 0.1 0.1 0.1 — 1.9 4.4 5.9 4.5 ...