Patent ID: 7449706

Claim:
A photocoupler, comprising: an input terminal; an output terminal; a first resistor with one end of the first resistor coupled to the input terminal; a first light emitting diode (LED) coupled to an opposing end of the first resistor thereby forming a first junction, the first LED configured to emit light upon receiving a first signal that is present at the first junction as a result of an input signal being applied to the input terminal and propagated through the first resistor; a first photodiode coupled to the output terminal of the photocoupler, the first photodiode configured to receive light emitted by the first LED and generate therefrom, a first portion of an output signal that is propagated to the output terminal; a signal compensation circuit comprising an alternating current (AC) amplifier coupled to the first junction, the AC amplifier configured to receive the first signal present at the first junction and generate therefrom, a compensation signal; a second resistor with a proximal end coupled to an output capacitor of the AC amplifier; a third resistor with one end coupled to a biasing voltage and an opposing end coupled to a distal end of the second resistor thereby forming a second junction at the distal end of the second resistor; a second LED coupled to the second junction, the second LED configured to emit light upon receiving the compensation signal from the second junction; and a second photodiode coupled to the output terminal of the photocoupler, the second photodiode configured to receive light emitted by the second LED and generate therefrom, a second portion of the output signal that is provided to the output terminal, the second portion operative to compensate for a current-voltage non-linearity present in the first portion of the output signal.