74HCT423D,118 NXP

74HC423 74HCT423 Dual retriggerable monostable multivibrator with reset Rev. 6 19 December 2011 Product data sheet 1. General description 74HC423 74HCT423 are high-speed Si-gate CMOS devices that are pin compatible with Low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC423 74HCT423 dual retriggerable monostable multivibrator with reset has two methods of output pulse width control. 1. The minimum pulse width is essentially determined by the selection of an external resistor (R ) and capacitor (C ), see Section 12.1. EXT EXT 2. Once triggered, the basic output pulse width may be extended by retriggering the gated active LOW-going edge input (nA) or the active HIGH-going edge input (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. Figure 10 and Figure 11 illustrate pulse control by reset. The nA and nB inputs Schmitt trigger action makes them highly tolerant to slower input rise and fall times. The 74HC423 74HCT423 are identical to the 74HC123 74HCT123 except that they cannot be triggered via the reset input. 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 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 C74HC423 74HCT423 NXP Semiconductors Dual retriggerable monostable multivibrator with reset 3. Ordering information Table 1. Ordering information Type number Package Temperature range Name Description Version 74HC423N 40 C to +125 C DIP16 plastic dual in-line package 16 leads (300 mil) SOT38-4 74HCT423N 74HC423D 40 C to +125 C SO16 plastic small outline package 16 leads SOT109-1 body width 3.9 mm 74HCT423D 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 74HCT423BQ body 2.5 3.5 0.85 mm 74HCT423DB 40 C to +125 C SSOP16 plastic shrink small outline package 16 leads SOT338-1 body width 5.3 mm 74HCT423PW 40 C to +125 C TSSOP16 plastic thin shrink small outline package 16 leads SOT403-1 body width 4.4 mm 4. Functional diagram 14 1CEXT 15 1REXT/CEXT S 13 1Q Q 1 1A T 4 1Q Q 2 1B RD 3 6 1RD 2CEXT 7 2REXT/CEXT S 5 2Q Q 9 2A T 12 Q 2Q 10 2B RD 11 2RD 001aah796 Fig 1. Functional Diagram 74HC HCT423 All information provided in this document is subject to legal disclaimers. NXP B.V. 2011. All rights reserved. Product data sheet Rev. 6 19 December 2011 2 of 24