| 摘要 |
<p>PURPOSE:To expand an operational margin against fluctuation in the characteristic of MOS transistors occurring in the manufacture by controlling the gate voltage of the MOS transistor for voltage-controlling of a sense amplifier such as P-ROM, corresponding to an electric current conducted through a ROM cell. CONSTITUTION:Since a MOSFET 6 is the same transistor as the ROM cell 30, if the channel width W and the channel width L f a MOSFET 1 and that 2, the same current is conducted through MOSFETs 2, 4, too. Therefore, if the current through the cell 30 is increased because of fluctuation in the power supply voltage or fluctuation in manufacture, a current through FETs 6, 2 also is increased. Accordingly, by making the W/L of a MOSFET 5 larger than the W/L of the FET 4, the resistance in apperance is increased to effect as a voltage control, hence the amplitude of the charge/discharge of digit lines can be regulated to be small, as a result, the operational margin can be expanded.</p> |
