The SN54/74LS247 thru SN54/74LS249 are BCD-to-Seven-Segment
Decoder/Drivers.
The LS247 and LS248 are functionally and electrically identical to the LS47
and LS48 with the same pinout configuration. The LS249 is a 16-pin version
of the 14-pin LS49 and includes full functional capability for lamp test and
ripple blanking which was not available in the LS49.
The composition of all characters, except the 6 and 9 are identical between
the LS247, 248, 249 and the LS47, 48 and 49. The LS47 thru 49 compose
the
and
without tails, the LS247 thru 249 compose the and with
the tails. The LS247 has active-low outputs for direct drive of indicators. The
LS248 and 249 have active-high outputs for driving lamp buffers.
All types feature a lamp test input and have full ripple-blanking input/output
controls. On all types an automatic leading and/or trailing-edge zero-blanking
control (RBI and RBO) is incorporated and an overriding blanking input (BI)
is contained which may be used to control the lamp intensity by pulsing or to
inhibit the output’s lamp test may be performed at any time when the BI/RBO
node is at high level. Segment identification and resultant displays are shown
below. Display pattern for BCD input counts above 9 are unique symbols to
authenticate input conditions.
LS247
SN54/74LS247
SN54/74LS248
SN54/74LS249
BCD-TO-SEVEN-SEGMENT
DECODERS/ DRIVERS
LOW POWER SCHOTTKY
J SUFFIX
CERAMIC
CASE 620-09
16
1
16
1
N SUFFIX
PLASTIC
CASE 648-08
•
Open-Collector Outputs Drive Indicators Directly
•
Lamp-Test Provision
•
Leading / Trailing Zero Suppression
LS248
•
Internal Pull-Ups Eliminate Need for External Resistors
•
Lamp-Test Provision
•
Leading / Trailing Zero Suppression
LS249
•
Open-Collector Outputs
•
Lamp-Test Provision
•
Leading / Trailing Zero Suppression
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
SN54LSXXXJ
Ceramic
SN74LSXXXN Plastic
SN74LSXXXDW SOIC
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
NUMERICAL DESIGNATIONS AND RESULTANT DISPLAYS
a
f
e
d
g
b
c
SEGMENT
IDENTIFICATION
FAST AND LS TTL DATA
5-402
SN54/74LS247
•
SN54/74LS248
•
SN54/74LS249
SN54 / 74LS248
SN54 / 74LS259
(TOP VIEW)
OUTPUTS
SN54 / 74LS247
(TOP VIEW)
OUTPUTS
VCC
16
f
15
g
14
a
13
b
12
c
11
d
10
e
9
VCC
16
f
15
g
14
a
13
b
12
c
11
d
10
e
9
f
g
a
b
BI/
c
d
e
f
g
a
b
BI/
c
d
e
B
C LT RBORBI D
A
B
C LT RBORBI D
A
1
B
2
C
3
LAMP
TEST
4
RB
OUT
PUT
5
RB
IN
PUT
6
D
7
A
8
GND
1
B
2
C
3
LAMP
TEST
4
RB
OUT
PUT
5
RB
IN
PUT
6
D
7
A
8
GND
INPUTS
INPUTS
INPUTS
INPUTS
ALL CIRCUIT TYPES FEATURE LAMP INTENSITY MODULATION CAPABILITY
DRIVER OUTPUTS
TYPE
SN54LS247
SN54LS248
SN54LS249
SN74LS247
SN74LS248
SN74LS249
ACTIVE
LEVEL
low
high
high
low
high
high
OUTPUT
CONFIGURATION
open-collector
2.0 kΩ pull-up
open-collector
open-collector
2.0 kΩ pull-up
open-collector
SINK
CURRENT
12 mA
2.0 mA
4.0 mA
24 mA
6.0 mA
8.0 mA
MAX
VOLTAGE
15 V
5.5 V
5.5 V
15 V
5.5 V
5.5 V
TYPICAL
POWER
DISSIPATION
35 mW
125 mW
40 mW
35 mW
125 mW
40 mW
LOGIC DIAGRAM
LS247
(13)
INPUT (7)
A
INPUT
B
(2)
(1)
(12)
OUTPUT
b
LS248, LS249
OUTPUT
a
INPUT (7)
A
INPUT
B
(1)
(13)
OUTPUT
a
(12)
OUTPUT
b
INPUT
C
(11)
OUTPUT
c
INPUT
C
(2)
(11)
OUTPUT
c
INPUT (6)
D
(10)
OUTPUT
d
INPUT (6)
D
(10)
OUTPUT
d
BI/RBO
BLANKING
INPUT OR
RIPPLE BLANKING
OUTPUT
(4)
(9)
OUTPUT
e
BLANKING
INPUT OR
RIPPLE BLANKING
OUTPUT
(4)
(9)
OUTPUT
e
(15)
(3)
OUTPUT
f
LAMP TEST
(3)
(15)
OUTPUT
f
LAMP TEST
INPUT
RBI
RIPPLE BLANKING
INPUT
(14)
(5)
OUTPUT
g
INPUT
RIPPLE BLANKING
INPUT
(5)
(14)
OUTPUT
g
FAST AND LS TTL DATA
5-403
SN54/74LS247
•
SN54/74LS248
•
SN54/74LS249
LS247
FUNCTION TABLE
DECIMAL
OR
FUNCTION
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
BI
RBI
LT
INPUTS
BI/RBO
LT
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
X
H
L
RBI
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
L
X
D
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
X
L
X
C
L
L
L
L
H
H
H
H
L
L
L
L
H
H
H
H
X
L
X
B
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
X
L
X
A
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
X
L
X
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
a
ON
OFF
ON
ON
OFF
ON
ON
ON
ON
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
ON
b
ON
ON
ON
ON
ON
OFF
OFF
ON
ON
ON
OFF
OFF
ON
OFF
OFF
OFF
OFF
OFF
ON
c
ON
ON
OFF
ON
ON
ON
ON
ON
ON
ON
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
ON
d
ON
OFF
ON
ON
OFF
ON
ON
OFF
ON
ON
ON
ON
OFF
ON
ON
OFF
OFF
OFF
ON
e
ON
OFF
ON
OFF
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
ON
f
ON
OFF
OFF
OFF
ON
ON
ON
OFF
ON
ON
OFF
OFF
ON
ON
ON
OFF
OFF
OFF
ON
g
OFF
OFF
ON
ON
ON
ON
ON
OFF
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
ON
2
3
4
OUTPUTS
NOTE
1
LS248, LS249
FUNCTION TABLE
DECIMAL
OR
FUNCTION
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
BI
RBI
LT
INPUTS
BI/RBO
LT
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
X
H
L
RBI
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
L
X
D
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
X
L
X
C
L
L
L
L
H
H
H
H
L
L
L
L
H
H
H
H
X
L
X
B
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
X
L
X
A
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
X
L
X
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
H
a
H
L
H
H
L
H
H
H
H
H
L
L
L
H
L
L
L
L
H
b
H
H
H
H
H
L
L
H
H
H
L
L
H
L
L
L
L
L
H
c
H
H
L
H
H
H
H
H
H
H
L
H
L
L
L
L
L
L
H
d
H
L
H
H
L
H
H
L
H
H
H
H
L
H
H
L
L
L
H
e
H
L
H
L
L
L
H
L
H
L
H
L
L
L
H
L
L
L
H
f
H
L
L
L
H
H
H
L
H
H
L
L
H
H
H
L
L
L
H
g
L
L
H
H
H
H
H
L
H
H
H
H
H
H
H
L
L
L
H
2
3
4
1
1
OUTPUTS
NOTE
1
H = HIGH Level, L = LOW Level, X = Irrelevant
NOTES: 1. The blanking input (BI) must be open or held at a high logic level when output functions 0 through 15 are desired. The ripple-blanking input (RBI) must
NOTES: 1.
be open or high if blanking of a decimal zero is not desired.
2. When a low logic level is applied directly to the blanking input (BI), all segment outputs are off regardless of the level of any other input.
3. When ripple-blanking input (RBI) and inputs A, B, C, and D are at a low level with the lamp test input high, all segment outputs go off and the
NOTES: 1.
ripple-blanking output (RBO) goes to a low level (response condition).
4. When the blanking input/ripple blanking output (BI/RBO) is open or held high and a low is applied to the lamp-test input, all segment outputs are on.
BI/RBO is wire-AND logic serving as blanking input (BI) and/or ripple-blanking output (RBO).
FAST AND LS TTL DATA
5-404
SN54/74LS247
GUARANTEED OPERATING RANGES
Symbol
VCC
TA
IOH
IOL
VO(off)
IO(on)
Supply Voltage
Operating Ambient Temperature Range
Output Current — High BI / RBO
Output Current — Low BI / RBO
Off-State Output Voltage a – g
On-State Output Current a – g
On-State Output Current
a – g
Parameter
54
74
54
74
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
– 50
1.6
3.2
15
12
24
Unit
V
°C
µA
mA
V
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
Output HIGH Voltage
BI / RBO
Output LOW Voltage
BI / RBO
Off-State Output Current
a–g
On-State Output Voltage
a–g
Input HIGH Current
0.1
Input LOW Current
Any Input, except BI/ RBO
BI / RBO
IOS
ICC
Short Circuit Current
BI / RBO (Note 1)
Power Supply Current
– 0.3
7.0
– 0.4
– 1.2
– 2.0
13
mA
mA
VCC = MAX
VCC = MAX
54
74
54, 74
74
54, 74
54, 74
74
0.25
0.35
2.4
2.4
– 0.65
4.2
4.2
0.25
0.35
0.4
0.5
250
0.4
0.5
20
IIH
0.8
– 1.5
V
V
V
V
V
µA
V
V
µA
mA
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 = 1.6 mA
IOL = 3.2 mA
VCC = VCC MIN,
VIN = VIL or VIH
per Truth Table
VOL
IO(off)
VO(on)
VCC = MAX, VIH = 2.0 V,
VO(off) = 15 V, VIL = MAX
IO(on) = 12 mA
IO(on) = 24 mA
VCC = MIN, VIH = 2.0 V,
VIL per Truth Table
VCC = MAX, VIN = 2.7 V
VCC = MAX, VIN = 7.0 V
VCC = MAX, VIN = 0.4 V
IIL
mA
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS
(VCC = 5.0 V, TA = 25°C)
Limits
Symbol
tPLH
tPHL
tPHL
tPLH
Parameter
Turn-Off Time from A Input
Turn-On Time from A Input
Turn-Off Time from RBI Input
Turn-On Time from RBI Input
Min
Typ
Max
100
100
100
100
Unit
ns
ns
Test Conditions
CL = 15 pF,
RL = 665
Ω
FAST AND LS TTL DATA
5-405
SN54/74LS248
GUARANTEED OPERATING RANGES
Symbol
VCC
TA
IOH
Supply Voltage
Operating Ambient Temperature Range
Output Current — High BI / RBO
Output Current — High
a – g
IOL
Output Current — Low BI / RBO
Output Current — Low
BI / RBO
Output Current — Low
a – g
Output Current — Low
a – g
Parameter
54
74
54
74
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
– 50
– 100
1.6
3.2
2.0
6.0
mA
Unit
V
°C
µA
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
VIH
VIL
VIK
VOH
IOH
Parameter
Input HIGH Voltage
54
Input LOW Voltage
74
Input Clamp Diode Voltage
Output HIGH Voltage
a – g and BI / RBO
Output Current
a–g
Output LOW Voltage
a–g
VOL
BI / RBO
54
74
54, 74
2.4
2.4
– 1.3
– 0.65
4.2
4.2
– 2.0
0.8
– 1.5
V
V
V
mA
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
VCC = MIN, VO = 0.85 V,
Input Conditions as for VOH
IOL = 2.0 mA
IOL = 6.0 mA
V
74
IIH
Input HIGH Current
Any Input, except BI/ RBO
Input LOW Current
Any Input, except BI/ RBO
BI / RBO
IOS
ICC
Short Circuit Current
BI / RBO (Note 1)
Power Supply Current
– 0.3
25
0.35
0.5
20
0.1
– 0.4
– 1.2
– 2.0
38
mA
mA
VCC = MAX
VCC = MAX
µA
mA
IOL = 1.6 mA
IOL = 3.2 mA
VCC = MAX, VIN = 2.7 V
VCC = MAX, VIN = 7.0 V
VCC = MAX, VIN = 0.4 V
VCC = MIN, VIH = 2.0 V,
VIL = per Truth Table
54, 74
74
54, 74
0.25
0.35
0.25
0.4
0.5
0.4
V
IIL
mA
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS
(VCC = 5.0 V, TA = 25°C)
Limits
Symbol
tPLH
tPHL
tPHL
tPLH
Parameter
Propagation Delay Time, High-to-Low-Level Output from A Input
Propagation Delay Time, Low-to-High-Level Output from A Input
Propagation Delay Time, High-to-Low-Level Output from RBI Input
Propagation Delay Time, Low-to-High-Level Output from RBI Input
Switching mode power supplies are used to convert one voltage into another. The efficiency of this type of power supply is usually very high, so in many applications, it replaces linear regulators. Sw...
Building a development environment and using UBOOT [Part 1] [color=#ff00][backcolor=rgb(255, 255, 255)][font=Verdana]HELPER2416 Development Board Student Aid Program[/font][/backcolor][/color] I am al...
Name: Single-chip display terminal Model: PVA050-256 The core circuit of Pingwang display control products is implemented by ALTERA's large-scale programmable integrated circuit (FPGA) EPM3128, with s...
There is a project, which is about making a simple switching power supply. I am required to use a comparator to implement overcurrent protection. Specifically, I connect a small resistor in series in ...
Power technology
京公网安备 11010802033920号
EEWORLD
