INDUSTRIALTEMPERATURERANGE

IDT74LVC138A

3.3VCMOS3-LINE TO 8-LINE DECODER/DEMULTIPLEXER

1

AUGUST 1999

INDUSTRIAL TEMPERATURE RANGE

The IDT logo is a registered trademark of Integrated Device Technology, Inc.

©1999 Integrated Device Technology, Inc.

DSC-4722/1

FEATURES:

• 0.5 MICRON CMOS Technology

• ESD > 2000V per MIL-STD-883, Method 3015; > 200V using

machine model (C = 200pF, R = 0)

• CMOS power levels (0.4

µµµµµ W typ. static)

• Rail-to-Rail output swing for increased noise margin

• All inputs, outputs, and I/Os are 5V tolerant

• Supports hot insertion

• Available in QSOP, SOIC, SSOP, and TSSOP packages

FUNCTIONAL BLOCK DIAGRAM

DRIVE FEATURES:

• High Output Drivers: ±24mA

• Reduced system switching noise

APPLICATIONS:

• 5V and 3.3V mixed voltage systems

• Data communication and telecommunication systems

IDT74LVC138A

DESCRIPTION:

The LVC138A 3-line to 8-line decoder/demultiplexer is built using

advanced dual metal CMOS technology. This device is designed for high-

performance memory-decoding or data-routing applications requiring very

short propagation delay times. In high performance memory systems, this

decoder minimizes the effects of system decoding. When employed with

high-speed memories utilizing a fast enable circuit, the delay times of these

decodersandtheenabletimeofthememoryareusuallylessthanthetypical

access time of the memory. This means that the effective system delay

introduced by the decoder is negligible.

The conditions at the binary-select inputs and the three enable inputs

selectoneofeightoutputlines.Twoactive-lowenableinputsandoneactive-

high enable input reduce the need for external gates or inverters when

expanding. A 24-line decoder can be implemented without external invert-

ers and a 32-line decoder requires only one inverter. An enable input can

be used as a data input for demultiplexing applications.

Inputs can be driven from either 3.3V or 5V devices. This feature allows

the use of this device as a translator in a mixed 3.3V/5V supply system.

The LVC138A has been designed with a ±24mA output driver. This

driver is capable of driving a moderate to heavy load while maintaining

speed performance.

3.3V CMOS

3-LINE TO 8-LINE

DECODER/DEMULTIPLEXER

WITH 5 VOLT TOLERANT I/O

Y0

15

G1

Y1

14

Y2

13

Y3

12

A

1

2

3

B

Select

Inputs

Data

Outputs

Enable

Inputs

G2A

G2B

6

4

5

C

Y4

11

Y5

10

Y6

9

Y7

7