SDAS210C − DECEMBER 1982 − REVISED JULY 1996
D Single Down / Up Count-Control Line
D Look-Ahead Circuitry Enhances Speed of
SN54ALS191A . . . J PACKAGE
SN74ALS191A . . . D OR N PACKAGE
(TOP VIEW)
Cascaded Counters
D Fully Synchronous in Count Modes
D Asynchronously Presettable With Load
D
B
QB
QA
CTEN
D/U
QC
QD
GND
Control
Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
A
CLK
RCO
MAX/MIN
LOAD
C
D
description
SN54ALS191A . . . FK PACKAGE
(TOP VIEW)
QB
B
NC
VCC
A
The ’ALS191A are synchronous 4-bit reversible
up/down binary counters. Synchronous counting
operation is provided by having all flip-flops
clocked simultaneously so that the outputs
change coincidentally with each other when
instructed by the steering logic. This mode of
operation eliminates the output counting spikes
normally
associated
with
asynchronous
(ripple-clock) counters.
QA
CTEN
NC
D/U
QC
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
CLK
RCO
NC
MAX/MIN
LOAD
QD
GND
NC
D
C
The outputs of the four flip-flops are triggered on
a low-to-high-level transition of the clock (CLK)
input if the count enable (CTEN) input is low. A
high at CTEN inhibits counting. The direction of
the count is determined by the level of the
down/up (D/U) input. When D/U is low, the counter
counts up, and when D/U is high, the counter
counts down.
4
NC − No internal connection
These counters feature a fully independent clock circuit. Changes at the control inputs (CTEN and D/U) that
modify the operating mode have no effect on the contents of the counter until clocking occurs. The function of
the counter is dictated solely by the conditions meeting the stable setup and hold times.
These counters are fully programmable. Each output can be preset to either level by placing a low on the LOAD
input and entering the desired data at the data inputs. The output changes to agree with the data inputs
independently of the level of the clock input. This feature allows the counters to be used as modulo-N dividers
by simply modifying the count length with the preset inputs.
CLK, D/U, and LOAD are buffered to lower the drive requirement, which significantly reduces the loading on
(current required by) clock drivers, for long parallel words.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 1996, Texas Instruments Incorporated
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#"!*!* .!!"/+ *%$" '$#0 * " &$#!)/ $)%*&
""0 !)) '!!&"&#+
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•
1
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
description (continued)
Two outputs are available to perform the cascading function: ripple clock and maximum/minimum count. The
latter output produces a high-level output pulse with a duration approximately equal to one complete cycle of
the clock while the count is minimum (0) counting down or maximum (15) counting up. The ripple-clock output
(RCO) produces a low-level output pulse under those same conditions, but only while the clock input is low. The
counter easily can be cascaded by feeding the ripple-clock output to the enable input of the succeeding counter
if parallel clocking is used, or to the clock input if parallel enabling is used. The maximum/minimum count
(MAX/MIN) output can be used to accomplish look ahead for high-speed operation.
The SN54ALS191A is characterized for operation over the full military temperature range of −55°C to 125°C.
The SN74ALS191A is characterized for operation from 0°C to 70°C.
logic symbol†
CTEN
D/U
CLK
LOAD
A
B
C
D
4
5
14
11
15
1
G1
CTRDIV16
M2 [DOWN] 2(CT=0)Z6
3(CT=15)Z6
M3 [UP]
1,2− / 1,3+
G4
6,1,4
13
MAX/MIN
RCO
C5
[1]
5D
[2]
10
[4]
9
[8]
† This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, J, and N packages.
2
12
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•
3
2
6
7
QA
QB
QC
QD
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
logic diagram (positive logic)
12
CTEN
D/U
CLK
LOAD
A
MAX/
MIN
4
13
RCO
5
14
11
15
3
S
QA
C1
1D
R
B
1
2
S
QB
C1
1D
R
C
10
6
S
C1
QC
1D
R
D
9
7
S
QD
C1
1D
R
Pin numbers shown are for the D, J, and N packages.
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•
3
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
typical load, count, and inhibit sequences
The following sequence is illustrated below:
1. Load (preset) to binary 13
2. Count up to 14, 15 (maximum), 0, 1, and 2
3. Inhibit
4. Count down to 1, 0 (minimum), 15, 14, and 13
LOAD
A
B
Data
Inputs
C
D
CLK
D/U
CTEN
QA
QB
QC
QD
MAX/MIN
RCO
13
14
15
0
1
2
2
Count Up
2
Inhibit
Load
4
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•
1
0
15
14
Count Down
13
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Operating free-air temperature range, TA: SN54ALS191A . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to 125°C
SN74ALS191A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
recommended operating conditions
SN54ALS191A
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
IOL
fclock
Low-level output current
tw
Pulse duration
tsu
High-level input voltage
NOM
MAX
MIN
NOM
MAX
4.5
5
5.5
4.5
5
5.5
2
High-level output current
th
Hold time
TA
Operating free-air temperature
2
0
V
−0.4
mA
20
0
20
16.5
25
20
Data before LOAD↑
25
20
CTEN before CLK↑
45
20
D/U before CLK↑
30
20
LOAD inactive before CLK↑
20
20
Data after LOAD↑
5
5
CTEN after CLK↑
0
0
0
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•
V
−0.4
LOAD low
−55
V
0.8
CLK high or low
D/U after CLK↑
UNIT
0.7
4
Clock frequency
Setup time
SN74ALS191A
MIN
8
mA
30
MHz
ns
ns
ns
0
125
0
70
°C
5
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
SN54ALS191A
TYP†
MAX
TEST CONDITIONS
MIN
VIK
VOH
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
II = − 18 mA
IOH = − 0.4 mA
VOL
VCC = 4.5 V
IOL = 4 mA
IOL = 8 mA
II
IIH
VCC = 5.5 V,
VCC = 5.5 V,
VI = 7 V
VI = 2.7 V
−1.5
VCC − 2
All others
VCC = 5.5 V,
UNIT
−1.5
V
0.25
0.4
V
0.35
0.5
VCC − 2
0.25
0.4
0.2
CTEN or CLK
IIL
SN74ALS191A
TYP†
MAX
MIN
VI = 0.4 V
0.1
mA
µA
20
20
−0.2
−0.2
−0.2
−0.1
mA
IO‡
VCC = 5.5 V,
VO = 2.25 V
−20
−112
−30
− 112
mA
ICC
VCC = 5.5 V,
All inputs at 0
12
22
12
22
mA
† All typical values are at VCC = 5 V, TA = 25°C.
‡ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
switching characteristics (see Figure 1)
PARAMETER
FROM
(OUTPUT)
TO
(OUTPUT)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500 Ω,
TA = MIN to MAX§
SN54ALS191A
MIN
fmax
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
tPLH
MAX
20
LOAD
Any Q
A, B, C, D
Any Q
CLK
RCO
CLK
Any Q
CLK
MAX/MIN
D/U
RCO
D/U
MAX/MIN
UNIT
SN74ALS191A
MIN
MAX
30
MHz
7
37
7
30
8
34
8
30
3
25
3
21
4
25
4
21
5
24
5
20
5
25
5
20
3
26
3
18
3
22
3
18
8
37
8
31
8
34
8
31
8
45
8
37
10
36
10
28
8
35
8
25
8
30
8
25
4
21
4
CTEN
RCO
tPHL
4
23
4
§ For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
18
tPHL
tPLH
tPHL
tPLH
6
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•
18
ns
ns
ns
ns
ns
ns
ns
ns
SDAS210C − DECEMBER 1982 − REVISED JULY 1996
PARAMETER MEASUREMENT INFORMATION
SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7V
RL = R1 = R2
VCC
S1
RL
R1
Test
Point
From Output
Under Test
CL
(see Note A)
From Output
Under Test
RL
Test
Point
CL
(see Note A)
CL
(see Note A)
LOAD CIRCUIT FOR
BI-STATE
TOTEM-POLE OUTPUTS
LOAD CIRCUIT
FOR OPEN-COLLECTOR OUTPUTS
3.5 V
Timing
Input
Test
Point
From Output
Under Test
LOAD CIRCUIT
FOR 3-STATE OUTPUTS
3.5 V
High-Level
Pulse
1.3 V
R2
1.3 V
1.3 V
0.3 V
0.3 V
tsu
Data
Input
tw
th
3.5 V
1.3 V
3.5 V
Low-Level
Pulse
1.3 V
0.3 V
1.3 V
0.3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATIONS
3.5 V
Output
Control
(low-level
enabling)
1.3 V
1.3 V
0.3 V
tPZL
Waveform 1
S1 Closed
(see Note B)
tPLZ
3.5 V
Input
tPHZ
1.3 V
0.3 V
tPHL
tPLH
VOH
In-Phase
Output
VOL
0.3 V
1.3 V
1.3 V
VOL
tPLH
tPHL
VOH
1.3 V
1.3 V
[3.5 V
1.3 V
tPZH
Waveform 2
S1 Open
(see Note B)
1.3 V
VOH
Out-of-Phase
Output
(see Note C)
0.3 V
[0 V
1.3 V
1.3 V
VOL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. When measuring propagation delay items of 3-state outputs, switch S1 is open.
D. All input pulses have the following characteristics: PRR ≤ 1 MHz, tr = tf = 2 ns, duty cycle = 50%.
E. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuits and Voltage Waveforms
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•
7
PACKAGE OPTION ADDENDUM
www.ti.com
14-Oct-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
5962-86840012A
ACTIVE
LCCC
FK
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
596286840012A
SNJ54ALS
191AFK
5962-8684001EA
ACTIVE
CDIP
J
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
5962-8684001EA
SNJ54ALS191AJ
Samples
5962-8684001FA
ACTIVE
CFP
W
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
5962-8684001FA
SNJ54ALS191AW
Samples
SN74ALS191AD
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS191A
Samples
SN74ALS191ADR
ACTIVE
SOIC
D
16
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS191A
Samples
SN74ALS191AN
ACTIVE
PDIP
N
16
25
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74ALS191AN
Samples
SNJ54ALS191AFK
ACTIVE
LCCC
FK
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
596286840012A
SNJ54ALS
191AFK
SNJ54ALS191AJ
ACTIVE
CDIP
J
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
5962-8684001EA
SNJ54ALS191AJ
Samples
SNJ54ALS191AW
ACTIVE
CFP
W
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
5962-8684001FA
SNJ54ALS191AW
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of