© Semiconductor Components Industries, LLC, 1999

December, 1999 – Rev. 6

1

Publication Order Number:

SN74LS47/D

SN74LS47

BCD to 7-Segment

Decoder/Driver

The SN74LS47 are Low Power Schottky BCD to 7-Segment

Decoder / Drivers consisting of NAND gates, input buffers and seven

AND-OR-INVERT gates. They offer active LOW, high sink current

outputs for driving indicators directly. Seven NAND gates and one

driver are connected in pairs to make BCD data and its complement

available to the seven decoding AND-OR-INVERT gates. The

remaining NAND gate and three input buffers provide lamp test,

blanking input / ripple-blanking output and ripple-blanking input.

The circuits accept 4-bit binary-coded-decimal (BCD) and,

depending on the state of the auxiliary inputs, decodes this data to

drive a 7-segment display indicator. The relative positive-logic output

levels, as well as conditions required at the auxiliary inputs, are shown

in the truth tables. Output configurations of the SN74LS47 are

designed to withstand the relatively high voltages required for

7-segment indicators.

These outputs will withstand 15 V with a maximum reverse current

of 250

µA. Indicator segments requiring up to 24 mA of current may

be driven directly from the SN74LS47 high performance output

transistors. Display patterns for BCD input counts above nine are

unique symbols to authenticate input conditions.

The SN74LS47 incorporates automatic leading and / or trailing-edge

zero-blanking control (RBI and RBO). Lamp test (LT) may be

performed at any time which the BI / RBO node is a HIGH level. This

device also contains an overriding blanking input (BI) which can be

used to control the lamp intensity by varying the frequency and duty

cycle of the BI input signal or to inhibit the outputs.

GUARANTEED OPERATING RANGES

Symbol

Parameter

Min

Typ

Max

Unit

Supply Voltage

4.75

5.0

5.25

V

Operating Ambient

Temperature Range

0

25

70

°C

Output Current – High

BI/RBO

–50

mA

Output Current – Low

BI/RBO

BI/RBO

3.2

mA

Off–State Output Voltage

a to g

15

V

On–State Output Current

a to g

24

mA

LOW

POWER

SCHOTTKY

SOIC

D SUFFIX

CASE 751B

http://onsemi.com

PLASTIC

N SUFFIX

CASE 648

16

1

16

1

Device

Package

Shipping

ORDERING INFORMATION

SN74LS47N

16 Pin DIP

2000 Units/Box

SN74LS47D

16 Pin

2500/Tape & Reel