MC74AC161
MC74ACT161
MC74AC163
MC74ACT163
Synchronous Presettable
Binary Counter
SYNCHRONOUS
PRESETTABLE
BINARY COUNTER
The MC74AC161/74ACT161 and MC74AC163/74ACT163 are high-speed
synchronous modulo-16 binary counters. They are synchronously presettable for
application in programmable dividers and have two types of Count Enable inputs
plus a Terminal Count output for versatility in forming synchronous multistage
counters. The MC74AC161/74ACT161 has an asynchronous Master Reset input
that overrides all other inputs and forces the outputs LOW. The MC74AC163/
74ACT163 has a Synchronous Reset input that overrides counting and parallel
loading and allows the outputs to be simultaneously reset on the rising edge of
the clock.
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•
•
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N SUFFIX
CASE 648-08
PLASTIC
Synchronous Counting and Loading
High-Speed Synchronous Expansion
Typical Count Rate of 125 MHz
Outputs Source/Sink 24 mA
′ACT161 and ′ACT163 Have TTL Compatible Inputs
VCC
16
TC
Q0
14
Q1
13
Q2
12
Q3
11
CET
PE
15
10
9
1
2
3
4
5
6
7
8
*R
CP
P0
P1
P2
P3
CEP
GND
D SUFFIX
CASE 751B-05
PLASTIC
LOGIC SYMBOL
PE P0 P1 P2 P3
CEP
CET
TC
CP
*R Q0 Q1 Q2 Q3
PIN NAMES
CEP
CET
CP
MR
SR
P0–P3
PE
Q 0 –Q 3
TC
Count Enable Parallel Input
Count Enable Trickle Input
Clock Pulse Input
(′161) Asynchronous Master Reset Input
(′163) Synchronous Reset Input
Parallel Data Inputs
Parallel Enable Input
Flip-Flop Outputs
Terminal Count Output
*MR for ′161
*SR for ′163
FACT DATA
5-1
MC74AC161 MC74ACT161 MC74AC163 MC74ACT163
MAXIMUM RATINGS*
Symbol
Parameter
Value
Unit
–0.5 to +7.0
V
V
VCC
DC Supply Voltage (Referenced to GND)
Vin
DC Input Voltage (Referenced to GND)
–0.5 to VCC +0.5
Vout
DC Output Voltage (Referenced to GND)
–0.5 to VCC +0.5
V
Iin
DC Input Current, per Pin
±20
mA
Iout
DC Output Sink/Source Current, per Pin
±50
mA
ICC
DC VCC or GND Current per Output Pin
±50
mA
Tstg
Storage Temperature
–65 to +150
°C
* Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended
Operating Conditions.
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Vin, Vout
2.0
5.0
6.0
′ACT
Supply Voltage
Max
′AC
VCC
Typ
4.5
5.0
5.5
DC Input Voltage, Output Voltage (Ref. to GND)
0
VCC
VCC @ 3.0 V
Input Rise and Fall Time (Note 1)
′AC Devices except Schmitt Inputs
tr, tf
Input Rise and Fall Time (Note 2)
′ACT Devices except Schmitt Inputs
TJ
IOL
VCC @ 4.5 V
10
VCC @ 5.5 V
V
25
8.0
Operating Ambient Temperature Range
IOH
40
Junction Temperature (PDIP)
TA
VCC @ 4.5 V
V
150
VCC @ 5.5 V
tr, tf
Unit
ns/V
ns/V
140
°C
85
°C
Output Current — High
–24
mA
Output Current — Low
24
mA
–40
1. Vin from 30% to 70% VCC; see individual Data Sheets for devices that differ from the typical input rise and fall times.
2. Vin from 0.8 V to 2.0 V; see individual Data Sheets for devices that differ from the typical input rise and fall times.
FACT DATA
5-3
25
