L298 Stepper Motor Controller IC

The L298 is an integrated monolithic circuit in a 15 - lead Multiwatt and PowerSO20 packages. It is a high voltage, high current dual full-bridge driver designed to accept standard TTL logic levels and drive inductive loads such as relays, solenoids, DC and stepping motors.

Two enable inputs are provided to enable or disable the device independently of the input signals. The emitters of the lower transistors of each bridge are connected together and the corresponding external terminal can be used for the connection of an external sensing resistor. An additional supply input is provided so that the logic works at a lower voltage.

POWER OUTPUT STAGE:
The L298 integrates two power output stages (A ; B). The power output stage is a bridge configuration and its outputs can drive an inductive load in common or differential mode, depending on the state of the inputs. The current that flows through the load comes out from the bridge at the sense output, an external resistor (RSA ; RSB.) allows to detect the intensity of this current.

INPUT STAGE:
Each bridge is driven by means of four gates the input of which are In1 ; In2 ; EnA and In3 ; In4 ; EnB. The In inputs set the bridge state when The En input is high ; a low state of the En input inhibits the bridge. All the inputs are TTL compatible.

Applications:
The sense output voltage can be used to control the current amplitude by chopping the inputs, or to provide over current protection by switching low the enable input. The brake function (Fast motor stop) requires that the Absolute Maximum Rating of 2 Amps must never be overcome. When the repetitive peak current needed from the load is higher than 2 Amps, a paralleled configuration can be chosen. An external bridge of diodes are required when inductive loads are driven and when the inputs of the IC are chopped ; Shottky diodes would be preferred.

Features:

• OPERATING SUPPLY VOLTAGE UP TO 46 V
• TOTAL DC CURRENT UP TO 4 A
• LOW SATURATION VOLTAGE
• OVER TEMPERATURE PROTECTION
• LOGICAL "0" INPUT VOLTAGE UP TO 1.5 V (HIGH NOISE IMMUNITY)