Switching regulator with controllable dead time and quick start

摘要

A driver circuit for driving a switching transistor includes a dead time calibration circuit and/or a quick start circuit. The dead time calibration circuit includes a delay comparator to compare a present delay between the low side switch turning off or the high side switch turning off and a voltage at a switch node between the high side switch and the low side switch to a past delay and a controller responsive to the comparison is configured to adjust the delay of an adjustable delay element coupled to a control terminal of a switching transistor. The quick start circuit includes a quick start signal generator having an adjustable delay element to generate a quick start signal having a pulse to turn on the switching transistor for a quick start interval, a quick start comparator configured to monitor the quick start signal, and a control circuit responsive to the comparison by the quick start comparator to adjust the delay of the delay element.

主权项

1. A driver circuit for driving a switching transistor of a switching regulator having a low side switch and a high side switch coupled to the low side switch at a switch node, comprising:
an adjustable delay element coupled between a control terminal of the high side switch and a control terminal of the low side switch and having a delay; and a dead time calibration circuit configured to calibrate a dead time between one of the low side or the high side switch turning off and the other one of the high side switch or the low side switch turning on, comprising:
a delay comparator configured to compare a present delay between the low side switch or the high side switch turning off and a voltage at the switch node to a past delay between the low side switch or the high side switch turning off and the voltage at the switch node; anda controller responsive to the comparison by the delay comparator to adjust the delay of the adjustable delay element.