HEF4538B Dual precision monostable multivibrator Rev. 9 10 December 2013 Product data sheet 1. General description The HEF4538B is a dual retriggerable-resettable monostable multivibrator. Each multivibrator has an active LOW trigger/retrigger input (nA), an active HIGH trigger/retrigger input (nB), an overriding active LOW direct reset input (nCD), an output (nQ) and its complement (nQ), and two pins (nREXT/CEXT, and nCEXT, always connected to ground) for connecting the external timing components C and R . EXT EXT Typical pulse width variation over the specified temperature range is 0.2 %. The multivibrator may be triggered by either the positive or the negative edges of the input pulse and will produce an accurate output pulse with a pulse width range of 10 s to infinity. The duration and accuracy of the output pulse are determined by the external timing components C and R . The output pulse width (t ) is equal to R C . EXT EXT W EXT EXT The linear design techniques in LOCMOS (Local Oxide CMOS) guarantee precise control of the output pulse width. A LOW level at nCD terminates the output pulse immediately. The trigger inputs Schmitt trigger action makes the circuit highly tolerant of slower rise and fall times. It operates over a recommended V power supply range of 3 V to 15 V referenced to V DD SS (usually ground). Unused inputs must be connected to V , V , or another input. DD SS 2. Features and benefits Tolerant of slow trigger rise and fall times Fully static operation 5 V, 10 V, and 15 V parametric ratings Standardized symmetrical output characteristics Specified from 40 C to +85 C and 40 C to +125 C Complies with JEDEC standard JESD 13-B 3. Ordering information Table 1. Ordering information All types operate from 40 C to +125 C. Type number Package Name Description Version HEF4538BP DIP16 plastic dual in-line package 16 leads (300 mil) SOT38-4 HEF4538BT SO16 plastic small outline package 16 leads body width 3.9 mm SOT109-1HEF4538B NXP Semiconductors Dual precision monostable multivibrator 4. Functional diagram ( 7 &( 75 ( 7& 4 4 ( 7 &( 75 ( 7& 4 4 DH D Fig 1. Functional diagram HEF4538B All information provided in this document is subject to legal disclaimers. NXP B.V. 2013. All rights reserved. Product data sheet Rev. 9 10 December 2013 2 of 18 & % & %