Signal processing circuit and solid-state image pickup device

摘要

A VI conversion circuit 40 _n inputs a voltage output from a hold circuit 30 _n, converts this input voltage to a current based on the resistance value of a resistor R₄₀, and outputs this current from a drain terminal of a MOS transistor T₄₀. An amp A₄₀ has an adequate open loop gain and MOS transistor T₄₀ operates in the saturated region. Here, if the resistance value of resistor R₄₀ is R, the current value I that is output from VI conversion circuit 40 _n is in the proportional relationship expressed by the equation, "I=V/R," with respect to the voltage V input into VI conversion circuit 40 _n.