Solid-state imaging device, package, and imaging system

A solid-state imaging device, comprising:

• a photoelectric conversion unit configured to generate a charge, wherein
• the photoelectric conversion unit comprises a material with lower band gap energy than silicon;
• a circuit substrate that is joined to the photoelectric conversion unit, wherein the circuit substrate includes
• a pixel signal generation circuit configured to generate a pixel signal of a voltage value based on the generated charge,
• a thermometer circuit configured to detect a temperature of the circuit substrate,
• a temperature control signal generation circuit configured to:
• acquire temperature information indicating the detected temperature;
• and
• generate a temperature control signal based on the acquired temperature information;
• an external terminal for a test, wherein
• the temperature control signal generation circuit is electrically connected to the external terminal for the test;
• and
• a multiplexer, wherein
• a plurality of circuits inside the circuit substrate including the temperature control signal generation circuit are connected to an input terminal of the multiplexer, and
• the external terminal for the test is connected to an output terminal of the multiplexer.