Patent ID: 7149098

Claim:
An over-power protection apparatus with programmable over-current threshold for a power converter, comprising: an oscillator, generating a pulse signal; a control unit, generating a clear signal in response to a current sense signal, a voltage feedback signal and a maximum power threshold of said power converter; a driving unit, connected to said oscillator and said control unit for generating a driving signal in response to said pulse signal and said clear signal; a threshold unit, connected to said driving unit for generating a current limit signal as said driving signal is in high-level; an over-power comparative unit, connected to said threshold unit for comparing said current limit signal and said current sense signal to generate a protection signal as said current sense signal is higher than said current limit signal; an accumulating trigger unit, connected to said over-power comparative unit and said oscillator for receiving said protection signal and said pulse signal, wherein said accumulating trigger unit accumulates and counts said protection signal, and further generates a first off-signal as said protection signal is enabled and the count of said protection signal reaches a predetermined value; and a latch unit, connected to said accumulating trigger unit and said driving unit for generating a latch signal to said driving unit in response to said first off-signal; wherein said driving unit latch-off said driving signal in response to said latch signal and adjusts a pulse width of said driving signal in response to said clear signal outputted by said control unit.