Trim circuit for power supply controller

摘要

A trim circuit for a power supply controller includes: a control circuit; at least a capacitance type programmable circuit connection; and a switching circuit, under control of the control circuit, the switching circuit selectively coupling the capacitance type programmable circuit connection to anyone of an operation voltage and a programming voltage, for determining a programming state of the capacitance type programmable circuit connection.

主权项

1. A trim circuit for a power supply controller, comprising:
a control circuit; at least a capacitance type programmable circuit connection; and a switching circuit, under control of the control circuit, the switching circuit selectively coupling the capacitance type programmable circuit connection to any one of an operation voltage and a programming voltage, for determining a programming state of the capacitance type programmable circuit connection, the switching including: a first switch selectively coupling the capacitance type programmable circuit connection to the programming voltage; and a second switch selectively coupling the capacitance type programmable circuit connection to the operation voltage; wherein the control circuit causes the first switch to be in a conduction state opposite to the second switch at all times, and the trim circuit further comprises: a current source, coupled between the operation voltage and the second switch, for constantly providing a reference current to the capacitance type programmable circuit connection.