Drive circuit for a switch in a switching converter

摘要

Disclosed is a drive circuit for providing a drive signal (S1) for a switch (M) in a switching converter, the drive circuit (100) comprising:
an output terminal (101) for providing the drive signal (S1); a soft-start terminal (104) for applying a soft-start signal (Vs) thereto;
a feedback terminal (102) for applying a feedback signal (FB) thereto;
the drive circuit being capable of assuming one of the following operation states:
an latch-off mode in which the drive circuit (100) is deactivated;
a normal operation mode, in which a duration of drive pulses of the drive signal is dependent on the feedback signal (FB);
a soft-start mode, in which a duration of drive pulses of the drive signal (S1) is dependent on a voltage (Vs) at the soft-start terminal (104);
and the drive circuit is adapted to assume the latch-off mode dependent on the voltage (Vs) at the soft-start terminal (104).