Patent ID: 6844782

Claim:
A temperature compensation circuit performing a temperature compensation with respect to a gain characteristic of a variable gain amplifier fabricated by MOS transistors and gain-controlled by an external gain control signal, the circuit comprising: a signal source which outputs a first signal corresponding to a temperature change of an ambient temperature to a predetermined temperature; and a multiplier which multiplies a gain control signal current corresponding to the external gain control signal and the first signal and outputs a second signal proportional to the temperature change to the variable gain amplifier, the signal source comprising a first MOS transistor whose source terminal is grounded, a second MOS transistor having gate and drain terminals connected to a gate of the first MOS transistor, and a resistor through which a source terminal of the second MOS transistor is grounded, and substantially identical currents flow through the drain terminals of the first and second MOS transistors, and the first and second MOS transistors operates in a weak inversion region.