The source transistors are used to switch the

power supplied to the motor winding, thus driving

a constant current through the winding.

It should be noted however, that is not permitted

to short circuit the outputs.

Internal circuitry is added in order to increase the

accuracy of the motor current particularly with low

current levels.

The circuit will stand any order of turn-on or turn-

values are then assumed.

APPLICATION INFORMATIONS (Note 1)

Some stepper motors are not designed for contin-

uous operation at maximum current. As the circuit

drives a constant current through the motor, its

temperature might increase exceedingly both at

low and high speed operation.

Also, some stepper motors have such high core

losses that they are not suited for switch mode

Figure 2: Principle Operating Sequence

L6219

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