Patent ID: 7656304

Claim:
A current sense circuit, comprising: a current sense resistor coupled to an input of the current sense circuit, the current sense resistor to receive a current to be sensed from the input of the current sense circuit to convert the current to be sensed to the current sense voltage; a first PN junction diode of a first transistor coupled to the current sense resistor; a second resistor coupled between a collector of the first transistor and a base of the first transistor; and a light emitting diode (LED) coupled to the first PN junction diode to provide a current sense threshold substantially a function of a difference between a forward voltage drop of the LED and a forward voltage drop of the first PN junction diode, the current sense threshold substantially equal to a voltage drop across the second resistor, the first PN junction diode coupled to be biased from the forward voltage drop of the LED, the LED coupled to the current sense resistor to generate an output when the current sense voltage from the current sense resistor reaches the current sense threshold.