CURRENT/VOLTAGE CONVERSION CIRCUIT AND ITS CONTROLLING METHOD

摘要

An input current flowing into a current-voltage conversion circuit 1 is converted to a voltage value at an output terminal SAIN and, then, a differential amplification circuit 5 amplifies and outputs a differential voltage between the voltage value and the reference voltage Vref. PMOS and NMOS transistors T1, T2 are connected between the output terminal SAIN and the power-supply voltage VCC. After the output terminal SAIN is precharged to the power-supply voltage VCC by making the transistors conductive, the current-voltage conversion operation is performed by making a voltage drop corresponding to the input current. The precharge operation charges the output terminal SAIN up to the power-supply voltage VCC and supplies charges to a common data line N3 and bit lines also to precharge them. Charging the path with great wiring capacitances from the output terminal SAIN through the common data line up to the bit lines can be performed with the NMOS transistor having a high current drivability and precharging up to the power-supply voltage VCC can be completed with the PMOS transistor T1.