1.

General description

The HEF4938B 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 (CEXT, always connected to ground, and

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

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.

2.

Features and benefits

40 C to +85 C

3.

Ordering information

HEF4938B

Dual precision monostable multivibrator

Rev. 6 — 15 November 2011

Product data sheet

Table 1.

Ordering information

All types operate from

Type number

Package

Name

Description

Version

HEF4938BP

DIP16

plastic dual in-line package; 16 leads (300 mil)

SOT38-4

HEF4938BT

SO16

plastic small outline package; 16 leads; body width 3.9 mm

SOT109-1