Patent ID: 6163191
Filing Date: 2000-12-19
Classification: H03K

Abstract:
A semiconductor integrated circuit device having a timer circuit, the timer circuit comprising: a regulated voltage circuit for outputting a regulated output voltage no greater than 1.0 V; a constant current circuit for producing a constant current having a value determined by the regulated output voltage of the regulated voltage circuit; a voltage comparing circuit for comparing an input voltage input to one terminal thereof with a reference voltage input to another terminal thereof; and a capacitive element connected to a constant current output terminal of the constant current circuit, the connecting point of the constant current output terminal of the constant current circuit and the capacitive element being connected to apply the input voltage to the voltage comparing circuit, so that a desired time period is determined by comparing a voltage at the terminal of the voltage comparing circuit connected to the capacitive element with the reference voltage at the other terminal of the comparing circuit; wherein the constant current circuit comprises a plurality of constant current transistors connected in parallel to each other, each constant current transistor having a different threshold voltage, and a trimming circuit comprising a switching transistor connected in series to each of the plurality of constant current transistors, the switching transistors selectively operate using trimming data, the constant current value of the constant current circuit is set to a desired value by the desired constant current value obtained by the trimming circuit.