74HC423D,653

74HC423 Dual retriggerable monostable multivibrator with reset Rev. 7 11 February 2016 Product data sheet 1. General description The 74HC423 is a dual retriggerable monostable multivibrator with output pulse width control by two methods. The basic pulse time is programmed by selection of an external resistor (R ) and capacitor (C ). Once triggered, the basic output pulse width may be EXT EXT extended by retriggering (nA) or (nB). By repeating this process, the output pulse period (nQ = HIGH, nQ = LOW) can be made as long as desired. When nRD is LOW, it forces the nQ output LOW, the nQ output HIGH and also inhibits the triggering. Schmitt-trigger action in the nA and nB inputs, makes the circuit highly tolerant to slower input rise and fall times. The 423 is identical to the 123 but cannot be triggered via the reset input. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of V . CC 2. Features and benefits DC triggered from active HIGH or active LOW inputs Retriggerable for very long pulses up to 100 % duty factor Direct reset terminates output pulse Schmitt-trigger action on all inputs except for the reset input Complies with JEDEC standard no. 7A Input levels: For 74HC423: CMOS level ESD protection: HBM JESD22-A114F exceeds 2000 V MM JESD22-A115-A exceeds 200 V Specified from 40 Cto+85 C and from 40 Cto+125 C 3. Ordering information Table 1. Ordering information Type number Package Temperature range Name Description Version 74HC423D 40 C to +125 C SO16 plastic small outline package 16 leads SOT109-1 body width 3.9 mm 74HC423BQ 40 C to +125 C DHVQFN16 plastic dual in-line compatible thermal enhanced very thin SOT763-1 quad flat package no leads 16 terminals body 2.5 3.5 0.85 mm74HC423 Nexperia Dual retriggerable monostable multivibrator with reset 4. Functional diagram 7 ( 57 ( &( 7 6 4 7 4 % 7 ( 57 ( &( 7 6 4 7 4 % DK D Fig 1. Functional Diagram ( 7 ( 7 5 ( 7& ( 7 5 ( 7& ( 7 5 6 4 4 4 7 4 4 % 4 5 D DK 5 DK D Fig 2. Logic symbol Fig 3. IEC Logic symbol 74HC423 All information provided in this document is subject to legal disclaimers Product data sheet Rev. 7 11 February 2016 2 of 19 Nexperia B.V. 2017. All rights reserved 5 % 5 5& & & & 5& & 5 5 4 4 & 5 5 4 4 &