MC74HC161A_13 Datasheet, PDF (2/15 Pages) ON Semiconductor – Presettable Counters

MC74HC161A, MC74HC163A
RESET 1
CLOCK 2
P0 3
P1 4
P2 5
P3 6
ENABLE P 7
GND 8
16 V_CC
15 ^RIPPLE
CARRY OUT
14 _Q0
13 Q1
12 Q2
11 Q3
10 ENABLE T
9 LOAD
Figure 1. Pin Assignment
FUNCTION TABLE
Clock
Reset*
L
H
H
H
H
Inputs
Output
Load Enable P Enable T
Q
X
X
L
X
H
H
H
L
H
X
X
Reset
X
Load Preset Data
H
Count
X
No Count
L
No Count
*HC163A only. HC161A is an Asynchronous Reset Device
H = high level, L = low level, X = don’t care
PRESET
DATA
INPUTS
P0 ³
P1 ⁴
P2 ⁵
P3 ⁶
CLOCK ²
COUNT
ENABLES
RESET ¹
LOAD ⁹
ENABLE P ⁷
ENABLE T ¹⁰
14 _Q0
13 _Q1
12 _Q2
11 _Q3
BCD OR
BINARY
OUTPUT
15 ^RIPPLE
CARRY
OUT
PIN 16 = V_CC
PIN 8 = GND
Figure 2. Logic Diagram
DEVICE/MODE TABLE
Device
Count
Mode
Reset Mode
HC161A
HC163A
Binary
Binary
Asynchronous
Synchronous
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