SN54147, SN54148, SN54LS147, SN54LS148

SN74147, SN74148 (TIM9907), SN74LS147, SN74LS148

10LINE TO 4LINE AND 8LINE TO 3LINE PRIORITY ENCODERS

SDLS053B − OCTOBER 1976 − REVISED MAY 2004

2

POST OFFICE BOX 655303

description/ordering information

These TTL encoders feature priority decoding of the inputs to ensure that only the highest-order data line is

encoded. The ’147 and ’LS147 devices encode nine data lines to four-line (8-4-2-1) BCD. The implied decimal

zero condition requires no input condition, as zero is encoded when all nine data lines are at a high logic level.

The ’148 and ’LS148 devices encode eight data lines to three-line (4-2-1) binary (octal). Cascading circuitry

(enable input EI and enable output EO) has been provided to allow octal expansion without the need for external

circuitry. For all types, data inputs and outputs are active at the low logic level. All inputs are buffered to represent

one normalized Series 54/74 or 54/74LS load, respectively.

ORDERING INFORMATION

TA

PACKAGE†

ORDERABLE

PART NUMBER

TOP-SIDE

MARKING

PDIP − N

Tube

SN74LS148N

SN74LS148N

0

°C to 70°C

SOIC − D

Tube

SN74LS148D

LS148

0

°C to 70°C

SOIC − D

Tape and reel

SN74LS148DR

LS148

SOP − NS

Tape and reel

SN74LS148NSR

74LS148

CDIP − J

Tube

SNJ54LS148J

SNJ54LS148J

−55

°C to 125°C

CFP − W

Tube

SNJ54LS148W

SNJ54LS148W

−55 C to 125 C

LCCC − FK

Tube

SNJ54LS148FK

SNJ54LS148FK

† Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are

available at www.ti.com/sc/package.

FUNCTION TABLE − ’147, ’LS147

INPUTS

OUTPUTS

1

2

3

4

5

6

7

8

9

D

C

B

A

H

H

H

H

H

H

H

H

H

H

H

H

H

X

XX

XX

XX

X

L

L

HH

L

X

XX

XX

XX

L

H

L

HH

H

X

XX

XX

X

L

H

H

H

LL

L

X

XX

XX

L

H

H

H

H

LL

H

X

X

X

X

L

HH

HH

H

LH

L

X

X

X

L

H

HH

HH

H

LH

H

X

X

L

HH

HH

HH

H

HL

L

X

L

H

HH

HH

HH

H

HLH

L

H

H

H

H

H

H

H

H

H

H

H

L

H = high logic level, L = low logic level, X = irrelevant