Variable gain amplifier circuit

A variable gain amplifier circuit comprising:

• a main circuit including a differential current circuit, a current divider circuit connected to a high potential side of the differential current circuit, and a load circuit connected to a high potential side of the current divider circuit, the main circuit being configured to generate differential output voltage signals by the load circuit in accordance with either differential input voltage signals or first differential current signals input to the differential current circuit;
• and
• a gain adjustment circuit configured to adjust a gain of the main circuit;
• wherein the differential current circuit generates second differential current signals in accordance with either the differential input voltage signals or the first differential current signals,
• wherein the current divider circuit generates non-inverted divided signals and inverted divided signals from the second differential current signals in accordance with a voltage difference between a first control voltage and a second control voltage, the non-inverted divided signals having a same phase as the second differential current signals, and the inverted divided signals having an opposite phase that is opposite to the second differential current signals, and generates third differential current signals by respectively adding the non-inverted divided signals and the inverted divided signals,
• wherein the load circuit converts the third differential current signals into the differential output voltage signals, and
• wherein the gain adjustment circuit includes a generation circuit configured to generate the first control voltage and the second control voltage in accordance with a setting signal, and a limit circuit configured to limit, by detecting an amplitude of the differential output voltage signals, the voltage difference to a limit value or greater so that the amplitude does not become lower than a setting voltage.