1

0

3

4

5

6

7

8

9

10

11

12

13

14

15

16

1

2

1

0

1

1

0

2

4

3

M

M

M

1

0

1

0

1

0

VCC2

VCC1

L293, L293D

www.ti.com

SLRS008D – SEPTEMBER 1986 – REVISED JANUARY 2016

8 Detailed Description

8.1 Overview

The L293 and L293D are quadruple high-current half-H drivers. These devices are designed to drive a wide array

of inductive loads such as relays, solenoids, DC and bipolar stepping motors, as well as other high-current and

high-voltage loads. All inputs are TTL compatible and tolerant up to 7 V.

Each output is a complete totem-pole drive circuit, with a Darlington transistor sink and a pseudo-Darlington

source. Drivers are enabled in pairs, with drivers 1 and 2 enabled by 1,2EN and drivers 3 and 4 enabled by

3,4EN. When an enable input is high, the associated drivers are enabled, and their outputs are active and in

phase with their inputs. When the enable input is low, those drivers are disabled, and their outputs are off and in

the high-impedance state. With the proper data inputs, each pair of drivers forms a full-H (or bridge) reversible

drive suitable for solenoid or motor applications.

On the L293, external high-speed output clamp diodes should be used for inductive transient suppression. On

the L293D, these diodes are integrated to reduce system complexity and overall system size. A VCC1 terminal,

separate from VCC2, is provided for the logic inputs to minimize device power dissipation. The L293 and L293D

are characterized for operation from 0°C to 70°C.

8.2 Functional Block Diagram

Output diodes are internal in L293D.

8.3 Feature Description

The L293x has TTL-compatible inputs and high voltage outputs for inductive load driving. Current outputs can get

up to 2 A using the L293.

Copyright © 1986–2016, Texas Instruments Incorporated

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Product Folder Links: L293 L293D