NSC 54LS192LMQB

54LS192/DM74LS192 Up/Down Decade Counter
with Separate Up/Down Clocks
General Description
The ’LS192 is an up/down BCD decade (8421) 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-toHIGH 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 stage 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.
Connection Diagram
Logic Symbol
Dual-In-Line Package
TL/F/10178 – 2
VCC e Pin 16
GND e Pin 8
TL/F/10178 – 1
Order Number 54LS192DMQB, 54LS192FMQB,
54LS192LMQB, DM74LS192M or DM74LS192N
See NS Package Number E20A, J16A,
M16A, N16E or W16A
Pin Names
CPU
CPD
MR
PL
P0 – P3
Q0 – Q3
TCD
TCU
Mode Select Table
Description
Count Up Clock Input
(Active Rising Edge)
Count Down Clock Input
(Active Rising Edge)
Asynchronous Master Reset Input
(Active HIGH)
Asynchronous Parallel Load Input
(Active LOW)
Parallel Data Inputs
Flip-Flop Outputs
Terminal Count Down (Borrow)
Output (Active LOW)
Terminal Count Up (Carry)
Output (Active LOW)
C1995 National Semiconductor Corporation
TL/F/10178
MR
PL
CPU
CPD
Mode
H
L
L
L
L
X
L
H
H
H
X
X
H
L
H
X
X
H
H
L
Reset (Asyn.)
Preset (Asyn.)
No Change
Count Up
Count Down
H e HIGH Voltage Level
L e LOW Voltage Level
X e Immaterial
RRD-B30M105/Printed in U. S. A.
54LS192/DM74LS192 Up/Down Decade Counter with Separate Up/Down Clocks
May 1992
Absolute Maximum Ratings (Note)
Note: The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
b 55§ C to a 125§ C
54LS
DM74LS
0§ C to a 70§ C
Storage Temperature Range
b 65§ C to a 150§ C
Recommended Operating Conditions
Symbol
54LS192
Parameter
DM74LS192
Units
Min
Nom
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
VCC
Supply Voltage
VIH
High Level Input Voltage
VIL
Low Level Input Voltage
IOH
High Level Output Voltage
IOL
Low Level Output Current
TA
Free Air Operating Temperature
ts (H)
ts (L)
Setup Time HIGH or LOW
Pn to PL
20
20
20
10
ns
th (H)
th (L)
Hold Time HIGH or LOW
Pn to PL
3
3
3
3
ns
tw (L)
CP Pulse Width LOW
17
17
ns
tw (L)
PL Pulse Width LOW
20
20
ns
tw (H)
MR Pulse Width HIGH
15
15
ns
trec
Recovery Time, MR to CP
3
3
ns
trec
Recovery Time, PL to CP
10
10
ns
2
2
V
0.7
0.8
V
b 0.4
b 0.4
mA
8
mA
70
§C
4
b 55
V
125
0
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
VI
Input Clamp Voltage
VCC e Min, II e b18 mA
VOH
High Level Output Voltage
VCC e Min, IOH e Max,
VIL e Max
54LS
2.5
DM74
2.7
VCC e Min, IOL e Max,
54LS
VOL
Low Level Output Voltage
Typ
(Note 1)
Max
Units
b 1.5
V
V
0.4
VIH e Min
DM74
0.5
IOL e 4 mA, VCC e Min
DM74
0.4
Input Current @ Max
Input Voltage
VCC e Max, VI e 10V
VI e 7V
DM74
High Level Input Current
IIL
IOS
II
IIH
ICC
DM54
V
0.1
mA
VCC e Max, VI e 2.7V
20
mA
Low Level Input Current
VCC e Max, VI e 0.4V
b 0.4
mA
Short Circuit
Output Current
VCC e Max
(Note 2)
Supply Current
VCC e Max, MR, PL e GND
Other Inputs e 4.5V
54LS
b 20
b 100
DM74
b 20
b 100
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
2
31
mA
mA
Switching Characterisitcs
VCC e a 0.5V, TA e a 25§ C (See Section 1 for waveforms and load configurations)
Symbol
RL e 2k
CL e 15 pF
Parameter
Min
Units
Max
fmax
Maximum Count Frequency
30
MHz
tPLH
tPHL
Propagation Delay
CPU or CPD to Qn
31
28
tPLH
tPHL
Propagation Delay
CPU to TCU
16
21
tPLH
tPHL
Propagation Delay
CPD to TCD
16
24
tPLH
tPHL
Propagation Delay
Pn to Qn
20
30
tPLH
tPHL
Propagation Delay
PL to Qn
32
30
tPHL
Propagation Delay, MR to Qn
25
ns
ns
ns
ns
Functional Description
TCU e Q0 # Q3 # CPU
TCD e Q0 # Q1 # Q2 # Q3 # CPD
Each circuit has an asynchronous parallel load capability
permitting the counter to be reset. 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.
The ’192 is an asynchronously presettable decade and 4-bit
binary synchronous up/down (reversible) counter. The operating modes of the ’192 decade counter and the ’193 binary counter are identical, with the only difference being the
count sequences as noted in the State Diagram. 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 ’192, 15 for the
’193), 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.
State Diagram
TL/F/10178 – 4
3
TL/F/10178 – 3
Logic Diagram
4
5
Physical Dimensions inches (millimeters)
Ceramic Leadless Chip Carrier Package (E)
Order Number 54LS192LMQB
NS Package Number E20A
16-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS192DMQB
NS Package Number J16A
6
Physical Dimensions inches (millimeters) (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS192M
NS Package Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS192N
NS Package Number N16E
7
54LS192/DM74LS192 Up/Down Decade Counter with Separate Up/Down Clocks
Physical Dimensions inches (millimeters) (Continued)
16-Lead Ceramic Flat Package (W)
Order Number 54LS192FMQB
NS Package Number W16A
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