INSULATED SYNCHRONOUS RECTIFICATION DC/DC CONVERTER

摘要

An external circuit element RSET is connected in use to an SET terminal. A synchronous rectification controller generates a pulse signal S1 based on a control time determined according to the state of the SET terminal. A driver switches on and off the synchronous rectification transistor according to the pulse signal S1. An abnormal state detection circuit is capable of detecting an open-circuit state and/or a short-circuit state that can occur in the SET terminal. When the abnormal state detection circuit detects such an open-circuit state and/or short-circuit state, the abnormal state detection circuit asserts a detection signal S11. When the detection signal S11 is asserted, a primary-side controller arranged on the primary side of the DC/DC converter is instructed to suspend the switching operation of a switching transistor.

主权项

1. A secondary-side controller that is arranged on a secondary side of an insulated synchronous rectification DC/DC converter, and that controls a synchronous rectification transistor, the secondary-side controller comprising:
a set terminal that is connected in use to an external circuit element; a synchronous rectification controller that generates a pulse signal based on a control time determined according to a state of the set terminal; a driver that switches on and off the synchronous rectification transistor according to the pulse signal; and an abnormal state detection circuit that is capable of detecting an open-circuit state and/or a short-circuit state that can occur in the set terminal, and that asserts a detection signal upon detection of such an open-circuit state and/or a short-circuit state, wherein, when the detection signal is asserted, the secondary-side controller instructs a primary-side controller arranged on a primary side of the DC/DC converter to suspend a switching operation of a switching transistor.