BIDIRECTIONAL CURRENT BUFFER (L293D):
The L293 and L293D are quadruple high-current half-H drivers. The L293 is designed to provide bidirectional drive currents of up to 1 A at voltages from 4.5 V to 36 V. The L293D is designed to provide bidirectional drive currents of up to 600-mA at voltages from 4.5 V to 36 V. All inputs are TTL compatible. Each output is a complete totem-pole drive circuit, with a Darlington transistor sink and a pseudo-Darlington source.
WHERE TO USE?
The most common use of bidirectional current buffers is to drive a motor in both directions. Both devices are also used to drive inductive loads such as relays, solenoids, dc and bipolar stepping motors, as well as other high-current/high-voltage loads in positive supply applications.
HOW TO USE?
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 & 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.
This one bidirectional current buffer IC can be used to drive 2 motors simultaneously as shown: