Patent ID: 6359494
Filing Date: 2002-03-19
Classification: G05F,H03K

Abstract:
A semiconductor integrated circuit device, comprising:a reference current generating circuit including a first MOS transistor having a gate connected to a first node having a first potential, a second MOS transistor having a gate and a drain connected to each other so as to constitute a diode, the gate and the drain being connected to a second node having a second potential, and a resistor connected between a source of the first MOS transistor and the second node; and a level shifter including a third MOS transistor applied with the first potential from a power supply through a load element, the third MOS transistor having a drain and a gate connected to each other so as to constitute a diode, the drain and the gate being connected to the first node having the first potential, and a fourth MOS transistor constituted as a diode by connecting a gate and a drain thereof to the source of the third MOS transistor and having a source applied with a reference voltage, wherein the third and the fourth MOS transistors of the level shifter comprise transistors a total sum of threshold voltages of which is substantially equal to a total sum of threshold voltages of the first and second MOS transistors of the reference current generating circuit, and generate a reference current in the resistor of the reference current generating circuit in accordance with a voltage applied to the gate of the first MOS transistor, a memory body having a function as a non-volatile memory; a charge pump circuit for generating a voltage necessary to write/erase data in/from the memory body, boosting ability thereof depending on a frequency of a driving signal for driving the charge pump circuit; and an oscillation circuit for generating the driving signal for driving the charge pump circuit in which an oscillation frequency thereof is varied in accordance with a power supply voltage, including a delay circuit having a reference current source for generating a current having a substantially constant current value, a capacitor connected at one end to the reference current source when an input signal is inverted, and an amplifier for amplifying a difference between a reference voltage and a voltage at the one end of the capacitor until the inversion of the input signal and outputting the difference, the difference increasing as the power supply voltage increases, wherein the reference current of the reference current source is generated by using a combination of the reference current generating circuit and the level shifter.