SN54/74LS247
SN54/74LS248
SN54/74LS249
BCD-TO-SEVEN-SEGMENT
DECODERS/DRIVERS
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.
BCD-TO-SEVEN-SEGMENT
DECODERS/ DRIVERS
LOW POWER SCHOTTKY
J SUFFIX
CERAMIC
CASE 620-09
16
1
N SUFFIX
PLASTIC
CASE 648-08
16
1
LS247
• Open-Collector Outputs Drive Indicators Directly
• Lamp-Test Provision
• Leading / Trailing Zero Suppression
16
1
LS248
• Internal Pull-Ups Eliminate Need for External Resistors
• Lamp-Test Provision
• Leading / Trailing Zero Suppression
ORDERING INFORMATION
LS249
• Open-Collector Outputs
• Lamp-Test Provision
• Leading / Trailing Zero Suppression
0
1
D SUFFIX
SOIC
CASE 751B-03
SN54LSXXXJ
Ceramic
SN74LSXXXN Plastic
SN74LSXXXDW SOIC
2
3
4
5
6
7
8
9
10
11
12
13
14
15
NUMERICAL DESIGNATIONS AND RESULTANT DISPLAYS
a
f
g
e
b
c
d
SEGMENT
IDENTIFICATION
FAST AND LS TTL DATA
5-1
