CIRCUIT CONVERTING A PAIR OF DIFFERENTIAL INPUT SIGNALS TO SINGLE-ENDED OUTPUT SIGNALS

摘要

A signal converting circuit, which has particular application as a pedestal clamp circuit for a video signal, includes a differential amplifier having a pair of transistors which produce first and second differential currents at the respective collectors thereof; a first circuit supplied with the first differential current and including a diode and a first resistor having a first resistance value connected in series between the collector of one of the transistors of the differential amplifier and a reference potential; a second circuit supplied with the second differential current and including a second resistor having a second resistance value and a transistor having its collector emitter path connected in series with the second resistor between the collector of the other transistor of the differential amplifier and the reference potential; and an output circuit for producing an output current in response to the second differential current and including a current mirror transistor having its base-collector path connected in parallel with the collector-emitter path of the transistor of the second circuit, wherein the current gain of the signal converting circuit is controlled by the resistance values of the first and second resistors.