FEEDBACK PROTECTION FROM ADJACENT TERMINAL SHORTS

摘要

This relates to detecting unwanted couplings between a protected terminal and an adjacent terminal of an IC controller of a power supply. The voltages across adjacent terminals are monitored. If the voltage difference between the terminals falls below a minimum threshold for greater than a first duration of time, an internal current source injects current into one of the terminals. If, within a second duration of time, the injected current pulls the voltage of the injected terminal to a voltage that causes the voltage difference between the terminals to be above the minimum threshold, it may be determined that a transient fault has occurred and been cleared or falsely detected. If, however, the injected current does not pull the voltage of the injected terminal to a voltage that causes the voltage between the adjacent terminals to be above the minimum threshold, the fault condition is confirmed and switching is disabled.

主权项

1. A controller for regulating a power converter, the controller comprising:
a first terminal; a second terminal adjacent to the first terminal; and fault detection circuitry coupled to the first terminal and the second terminal, wherein the fault detection circuitry is configured to:
detect when a difference between a first voltage at the first terminal and a second voltage at the second terminal is less than a threshold value for a first duration of time;supply an injection current to the first terminal for a second duration of time in response to detecting that the difference between the first voltage and the second voltage is less than the threshold value for greater than the first duration of time; andoutput a fault signal in response to the difference between the first voltage and the second voltage being less than the threshold value after the second duration of time.