Apparatus and method for slew rate control

摘要

The slew rate of a transistor is controlled. Upon a transition of a MOSFET control signal, an operating voltage of the MOSFET is measured and a determination of whether the voltage is between a predetermined set of values is made. Based upon the determination, a counter is incremented, and the count of the counter corresponding slew rate. The turn-on current of the MOSFET is controlled based upon the count.

主权项

1. A method of controlling a slew rate of a transistor, comprising:
upon a first transition of a MOSFET control signal from a low to a high value, measuring an operating voltage of a MOSFET and determining whether the operating voltage is between a first predetermined set of values, and when the operating voltage is between the first predetermined set of values incrementing a first counter, a first count of the first counter corresponding to a rise time slew rate of the MOSFET control signal; controlling a turn-on current of the MOSFET based upon the first count; subsequently upon a second transition of a MOSFET control signal from a high to a low value, measuring the operating voltage of the MOSFET, and determining whether the operating voltage is between a second predetermined set of values, and when the operating voltage is within the second predetermined set of values incrementing a second counter, a second count of the second counter corresponding to a fall time slew rate of the MOSFET control signal; controlling a turn-off current of the MOSFET based upon the second count.