74156 IC Dual 2-Line to 4-Line Decoders/Demultiplexer DIP-16

Description

74
156 IC Dual 2-Line to 4-Line Decoders/Demultiplexer DIP-16

The 74156 IC is a dual 2-line to 4-line decoder/demultiplexer designed for digital logic applications. It comes in a standard DIP-16 package and is part of the TTL logic family. Each decoder within the IC can decode a 2-bit binary input into one of four mutually exclusive outputs, making it useful in memory addressing, data routing, and control applications. The IC includes enable inputs that allow independent control of each decoder, supporting flexible circuit designs. With active-low outputs, the 74156 is commonly employed in systems requiring efficient selection of data lines, expansion of I/O, or implementation of demultiplexing functions. Its reliable performance, compatibility with standard TTL devices, and ease of integration make it suitable for educational projects, digital circuits, and microprocessor-based systems.

Features

Dual 2-to-4 line decoder/demultiplexer in a single package.

Active-low outputs for easy integration with TTL logic systems.

Independent enable inputs for each decoder, allowing flexible control.

Can be used for decoding binary inputs or for demultiplexing data lines.

Standard DIP-16 package for easy handling and prototyping.

High-speed TTL logic compatibility.

Low power consumption relative to older logic families.

Reliable operation for memory addressing, data routing, and control applications.

Widely used in digital systems, microprocessor interfacing, and educational electronics.

Pin Layout

Pin Configuration

Pin No.

Pin Name

Description

1

1C

Data / Select Input C for Decoder 1

2

1G’

Enable Input (Active Low) for Decoder 1

3

1B

Select Input B for Decoder 1

4

1Y3

Output Y3 of Decoder 1 (Active Low)

5

1Y2

Output Y2 of Decoder 1 (Active Low)

6

1Y1

Output Y1 of Decoder 1 (Active Low)

7

1Y0

Output Y0 of Decoder 1 (Active Low)

8

GND

Ground (0V Reference)

9

2Y0

Output Y0 of Decoder 2 (Active Low)

10

2Y1

Output Y1 of Decoder 2 (Active Low)

11

2Y2

Output Y2 of Decoder 2 (Active Low)

12

2Y3

Output Y3 of Decoder 2 (Active Low)

13

2B

Select Input B for Decoder 2

14

2G’

Enable Input (Active Low) for Decoder 2

15

2C

Data / Select Input C for Decoder 2

16

VCC

Supply Voltage (+5V for TTL)

Specifications

Parameter

Test Conditions / Notes

Typical Value

Units

VOL (when IOL = 4 mA)

VCC = 4.5 V, output low current = 4 mA

0.25

V

VOL (when IOL = 8 mA)

VCC = 4.5 V, output low current = 8 mA

0.35

V

IOH (High-level output current)

VCC = 4.5 V, VOH = 5.5 V

0.1

mA

ICCL (Supply current, low outputs)

VCC = 5.5 V

5

mA

Input leakage current, high (IIH)

VCC = 5.5 V, VI = 2.7 V

20

µA

Input leakage current, low (IIL)

VCC = 5.5 V, VI = 0.4 V

–0.1

µA

Propagation delay, tPLH / tPHL

A, B → any Y (CL = 50 pF, RL = 500 Ω)

25 to 55

ns

Applications

Memory Address Decoding.

Data Routing / Demultiplexing.

I/O Expansion.

Microprocessor & Microcontroller Interfacing.

Signal Selection.

Control Systems.

LED / Display Driving.

Programmable Logic & Digital Systems.

Educational & Training Kits.

Package Contents

1 x
74156 IC Dual 2-Line to 4-Line Decoders/Demultiplexer DIP-16

Datasheet

74156