EPROM DEVICE

PURPOSE:To reduce a leak current at a non-selecting word line without losing a write speed by applying a write high voltage to the load means of a word line only at write operation by means of a switch MOSFET and boosting a gate voltage with a bootstrap circuit utilizing a write control signal. CONSTITUTION:At write operation, a high voltage is applied to a high voltage terminal Vpp, the write control signal we is brought into a low level, MOSFETs Q45, Q47 are turned off and the gate voltage of an MOSFETQ50 goes to a high level such as Vpp-2Vth through MOSFETQ48, 49. On the other hand, since an MOSFETQ59 is turned on while a delay signal we' is changed to a low level, a bootsrrap capacitor CB is charged up to a high level according to the gate voltage of the MOSFETQ50. Since the gate voltage of the MOSFETQ50 is brought into a high voltage being over the high voltage Vpp through the bootstrap operation, a high voltage Vpp' almost equal to the high voltage Vpp is applied to a depletion MOSFETQ40 or the like being a load.