HEF4538B_Q100 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 2 — 10 December 2013 4 of 17
NXP Semiconductors
HEF4538B-Q100
Dual precision monostable multivibrator
5.2 Pin description
6. Functional description
[1] H = HIGH voltage level; L = LOW voltage level; X = don’t care;
= positive-going transition; = negative-going transition;
= one HIGH level output pulse, with the pulse width determined by C
ext
and R
ext
;
= one LOW level output pulse, with the pulse width determined by C
ext
and R
ext
.
Table 2. Pin description
Symbol Pin Description
1CEXT, 2CEXT 1, 15 external capacitor connection (always connected to ground)
1REXT/CEXT, 2REXT/CEXT 2, 14 external capacitor/resistor connection
1CD
, 2CD 3, 13 direct reset input (active LOW)
1B, 2B 4, 12 input (LOW-to-HIGH triggered)
1A
, 2A 5, 11 input (HIGH-to-LOW triggered)
1Q, 2Q 6, 10 output
1Q
, 2Q 7, 9 complementary output (active LOW)
V
SS
8 ground supply voltage
V
DD
16 supply voltage
Table 3. Function table
Inputs Outputs
nA nB nCD nQ nQ
LH
H H
XXLLH
