HCF40103B_02 Datasheet, PDF (2/14 Pages) STMicroelectronics – 8-STAGE PRESETTABLE SYNCHRONOUS 8 BIT BINARY DOWN COUNTERS

HCF40103B
inputs are high at the time of zero count, the
counters will jump to the maximum count, giving a
counting sequence of 256 clock pulses long.
IINPUT EQUIVALENT CIRCUIT
HCF40103B may be cascaded using the CI/CE
input and the CO/ZD output, in either a
synchronous or ripple mode.
PIN DESCRIPTION
PIN No
1
2
3
4, 5, 6, 7, 10,
11, 12, 13
9
14
15
8
16
SYMBOL
CLOCK
CLEAR
CI/CE
NAME AND FUNCTION
Clock Input (LOW to
HIGH edge triggered)
Asynchronous Master
Reset Input (Active Low)
Terminal Enable Input
J0 to J7 Jam Inputs
APE
CO/ZD
SPE
V_SS
V_DD
Asynchronous Preset
Enable Inputs(Active Low)
Terminal Count Output
(Active Low)
Synchronous Preset
Enable Input (Active Low)
Negative Supply Voltage
Positive Supply Voltage
FUNCTIONAL DIAGRAM
TRUTH TABLES
CLR
CONTROL INPUTS
APE
SPE
CI/CE
PRESET MODE
H
H
H
H
H
H
H
L
Synchronous
H
H
L
X
H
L
X
X
Asynchronous
L
X
X
X
X : Don’t Care
Clock connected to Clock input
Synchronous Operation : changes occur on negative to positive clock transitions.
ACTION
Inhibit Counter
Count Down
Preset on Next Positive Clock Transition
Preset Asynchronously
Clear to Maximum Count
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