| 摘要 |
<p>PURPOSE:To make a circuit simple, to reduce power consumption and to use a power supply voltage for a wide range by adjusting a voltage value at the time of reading to a prescribed value with respect to the threshold value of a MOS transistor. CONSTITUTION:At the time other than a write-in mode, a control circuit 153 is in a state where the gates of MOS transistors TR151, 154 are at 0 volt and TR154 is off. Then, the gate voltage of TR152 is determined by N-channel enhancement type TR155-158 for a bias circuit, which are serially connected between a Vcc voltage terminal 15a and a ground terminal, and a resistor 159. The voltage value at the time of read-out is adjusted to be lower than the threshold value of the MOS type TR152 at the time when the electron of a floating gate is injected but higher than the threshold value of the TR154 at the time when it is not injected. Consequently, since a reference voltage generating circuit and a sense amplifier are unnecessitated, the circuit is simplified, the electric consumption is reduced, and the use of current voltage in a wider range is made possible.</p> |
