MC74HC4020A_14 Datasheet, PDF (6/8 Pages) ON Semiconductor – 14-Stage Binary Ripple Counter

MC74HC4020A
APPLICATIONS INFORMATION
Time−Base Generator
A 60Hz sinewave obtained through a 1.0 Megohm resistor
connected directly to a standard 120 Vac power line is
applied to the input of the MC54/74HC14A, Schmitt-trigger
inverter. The HC14A squares−up the input waveform and
feeds the HC4020A. Selecting outputs Q5, Q10, Q11, and
Q12 causes a reset every 3600 clocks. The HC20 decodes the
counter outputs, produces a single (narrow) output pulse,
and resets the binary counter. The resulting output frequency
is 1.0 pulse/minute.
V_CC
V_CC
120Vac
60Hz
1.0M
≥20pF
1/6 of HC14A
NOTE:
Ground MUST be isolated
by a transformer or
opto−isolator for safety
reasons.
HC4020A
13
Clock
Q5
12
Q10
10
Q11
9
Q12
1.0 Pulse/Minute
1
1/2
HC20
8
2
4
5
1/2
HC20
6
Output
Figure 8. Time−Base Generator
ORDERING INFORMATION
Device
Package
Shipping^†
MC74HC4020ADG
SOIC−16
(Pb−Free)
48 Units / Rail
MC74HC4020ADR2G
SOIC−16
(Pb−Free)
2500 / Tape & Reel
MC74HC4020ADTR2G
TSSOP−16
(Pb−Free)
2500 / Tape & Reel
NLV74HC4020ADTR2G*
TSSOP−16
(Pb−Free)
2500 / Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
*NLV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q100 Qualified and PPAP
Capable.
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