PRESETTABLE BCD/DECADE
UP/DOWN COUNTER
PRESETTABLE 4-BIT BINARY
UP/DOWN COUNTER
The SN54/74LS192 is an UP/DOWN BCD Decade (8421) Counter and the
SN54/74LS193 is an UP/DOWN MODULO-16 Binary Counter. Separate
Count Up and Count Down Clocks are used and in either counting mode the
circuits operate synchronously. The outputs change state synchronous with
the LOW-to-HIGH transitions on the clock inputs.
Separate Terminal Count Up and Terminal Count Down outputs are
provided which are used as the clocks for a subsequent stages without extra
logic, thus simplifying multistage counter designs. Individual preset inputs
allow the circuits to be used as programmable counters. Both the Parallel
Load (PL) and the Master Reset (MR) inputs asynchronously override the
clocks.
SN54/74LS192
SN54/74LS193
PRESETTABLE BCD/ DECADE
UP/ DOWN COUNTER
PRESETTABLE 4-BIT BINARY
UP/ DOWN COUNTER
LOW POWER SCHOTTKY
J SUFFIX
CERAMIC
CASE 620-09
16
1
•
•
•
•
•
•
•
Low Power . . . 95 mW Typical Dissipation
High Speed . . . 40 MHz Typical Count Frequency
Synchronous Counting
Asynchronous Master Reset and Parallel Load
Individual Preset Inputs
Cascading Circuitry Internally Provided
Input Clamp Diodes Limit High Speed Termination Effects
16
1
N SUFFIX
PLASTIC
CASE 648-08
CONNECTION DIAGRAM DIP
(TOP VIEW)
VCC
16
P0
15
MR
14
TCD
13
TCU
12
PL
11
P2
10
P3
9
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
NOTE:
The Flatpak version
has the same pinouts
(Connection Diagram) as
the Dual In-Line Package.
SN54LSXXXJ
SN74LSXXXN
SN74LSXXXD
Ceramic
Plastic
SOIC
1
P1
2
Q1
3
Q0
4
CPD
5
CPU
6
Q2
7
Q3
8
GND
LOGIC SYMBOL
11
15
1
10
9
PIN NAMES
LOADING
(Note a)
HIGH
LOW
0.25 U.L.
0.25 U.L.
0.25 U.L.
0.25 U.L.
0.25 U.L.
5 (2.5) U.L.
5 (2.5) U.L.
5 (2.5) U.L.
5
4
CPU
CPD
PL
P0 P1 P2
P3
TCU
TCD
CPU
CPD
MR
PL
Pn
Qn
TCD
TCU
Count Up Clock Pulse Input
Count Down Clock Pulse Input
Asynchronous Master Reset (Clear) Input
Asynchronous Parallel Load (Active LOW) Input
Parallel Data Inputs
Flip-Flop Outputs (Note b)
Terminal Count Down (Borrow) Output (Note b)
Terminal Count Up (Carry) Output (Note b)
0.5 U.L.
0.5 U.L.
0.5 U.L.
0.5 U.L.
0.5 U.L.
10 U.L.
10 U.L.
10 U.L.
12
MR Q0 Q1 Q2 Q3
14
3
2
6
7
13
NOTES:
a. 1 TTL Unit Load (U.L.) = 40
µA
HIGH/1.6 mA LOW.
b. The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)
b.
Temperature Ranges.
VCC = PIN 16
GND = PIN 8
FAST AND LS TTL DATA
5-351
SN54/74LS192
•
SN54/74LS193
FUNCTIONAL DESCRIPTION
The LS192 and LS193 are Asynchronously Presettable
Decade and 4-Bit Binary Synchronous UP / DOWN (Revers-
able) Counters. The operating modes of the LS192 decade
counter and the LS193 binary counter are identical, with the
only difference being the count sequences as noted in the
State Diagrams. Each circuit contains four master/slave
flip-flops, with internal gating and steering logic to provide
master reset, individual preset, count up and count down
operations.
Each flip-flop contains JK feedback from slave to master
such that a LOW-to-HIGH transition on its T input causes the
slave, and thus the Q output to change state. Synchronous
switching, as opposed to ripple counting, is achieved by
driving the steering gates of all stages from a common Count
Up line and a common Count Down line, thereby causing all
state changes to be initiated simultaneously. A LOW-to-HIGH
transition on the Count Up input will advance the count by one;
a similar transition on the Count Down input will decrease the
count by one. While counting with one clock input, the other
should be held HIGH. Otherwise, the circuit will either count by
twos or not at all, depending on the state of the first flip-flop,
which cannot toggle as long as either Clock input is LOW.
The Terminal Count Up (TCU) and Terminal Count Down
(TCD) outputs are normally HIGH. When a circuit has reached
the maximum count state (9 for the LS192, 15 for the LS193),
the next HIGH-to-LOW transition of the Count Up Clock will
cause TCU to go LOW. TCU will stay LOW until CPU goes
HIGH again, thus effectively repeating the Count Up Clock,
but delayed by two gate delays. Similarly, the TCD output will
go LOW when the circuit is in the zero state and the Count
Down Clock goes LOW. Since the TC outputs repeat the clock
waveforms, they can be used as the clock input signals to the
next higher order circuit in a multistage counter.
Each circuit has an asynchronous parallel load capability
permitting the counter to be preset. When the Parallel Load
(PL) and the Master Reset (MR) inputs are LOW, information
present on the Parallel Data inputs (P0, P3) is loaded into the
counter and appears on the outputs regardless of the
conditions of the clock inputs. A HIGH signal on the Master
Reset input will disable the preset gates, override both Clock
inputs, and latch each Q output in the LOW state. If one of the
Clock inputs is LOW during and after a reset or load operation,
the next LOW-to-HIGH transition of that Clock will be
interpreted as a legitimate signal and will be counted.
MODE SELECT TABLE
MR
H
L
L
L
L
PL
X
L
H
H
H
CPU
X
X
H
H
CPD
X
X
H
H
MODE
Reset (Asyn.)
Preset (Asyn.)
No Change
Count Up
Count Down
L = LOW Voltage Level
H = HIGH Voltage Level
X = Don’t Care
= LOW-to-HIGH Clock Transition
FAST AND LS TTL DATA
5-354
SN54/74LS192
•
SN54/74LS193
GUARANTEED OPERATING RANGES
Symbol
VCC
TA
IOH
IOL
Supply Voltage
Operating Ambient Temperature Range
Output Current — High
Output Current — Low
Parameter
54
74
54
74
54, 74
54
74
Min
4.5
4.75
– 55
0
Typ
5.0
5.0
25
25
Max
5.5
5.25
125
70
– 0.4
4.0
8.0
Unit
V
°C
mA
mA
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
VIH
VIL
VIK
VOH
Parameter
Input HIGH Voltage
54
Input LOW Voltage
74
Input Clamp Diode Voltage
54
Output HIGH Voltage
74
54, 74
VOL
Output LOW Voltage
74
Input HIGH Current
0.1
Input LOW Current
Short Circuit Current (Note 1)
Power Supply Current
– 20
– 0.4
– 100
34
0.35
0.5
20
IIH
IIL
IOS
ICC
V
µA
mA
mA
mA
mA
2.7
3.5
0.25
0.4
V
V
2.5
– 0.65
3.5
0.8
– 1.5
V
V
Min
2.0
0.7
V
Typ
Max
Unit
V
Test Conditions
Guaranteed Input HIGH Voltage for
All Inputs
Guaranteed Input LOW Voltage for
All Inputs
VCC = MIN, IIN = – 18 mA
VCC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
IOL = 4.0 mA
IOL = 8.0 mA
VCC = VCC MIN,
VIN = VIL or VIH
per Truth Table
VCC = MAX, VIN = 2.7 V
VCC = MAX, VIN = 7.0 V
VCC = MAX, VIN = 0.4 V
VCC = MAX
VCC = MAX
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS
(TA = 25°C)
Limits
Symbol
fMAX
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPHL
Parameter
Maximum Clock Frequency
CPU Input to
TCU Output
CPD Input to
TCD Output
Clock to Q
PL to Q
MR Input to Any Output
Min
25
Typ
32
17
18
16
15
27
30
24
25
23
26
24
24
24
38
47
40
40
35
Max
Unit
MHz
ns
ns
ns
ns
ns
Test Conditions
VCC = 5.0 V
CL = 15 pF
FAST AND LS TTL DATA
5-355
Electronics Design Contest
京公网安备 11010802033920号
EEWORLD
