MC74HC4040AD ONSEMI [ON Semiconductor], MC74HC4040AD Datasheet - Page 7

• Manufacturer Part Number: MC74HC4040AD
• Description: 12−Stage Binary Ripple Counter High−Performance Silicon−Gate CMOS
• Manufacturer: ONSEMI [ON Semiconductor]

Time−Base Generator
connected to a 120 Vac power line through a step down
transformer is applied to the input of the MC54/74HC14A,
Schmitt-trigger inverter. The HC14A squares−up the input
120Vac
A 60Hz sinewave obtained through a 100 K resistor
60Hz
NOTE:
Reset
Clock
Q10
Q12
Q11
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Q9
Ground MUST be isolated
by a transformer or
opto−isolator for safety
reasons.
1
1.0M
≥20pF
2
4
8
APPLICATIONS INFORMATION
Figure 9. Time−Base Generator
Figure 8. Timing Diagram
16
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MC74HC4040A
32
Clock
HC4040A
7
V
64
CC
waveform and feeds the HC4040A. 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.
Q10
Q12
Q11
Q5
128
13
12
10
9
256
HC20
1/2
512
8
1024
1
2
4
5
HC20
2048
1/2
6
4096
1.0 Pulse/Minute
Output