Reference voltage generating circuit and reference current generating circuit

Abstract

There is provided a reference current generation circuit generating a minute reference current while reducing the dimension of a reference resistance. When an output voltage of a regulator 14 is divided by means of a resistance division circuits consisting of resistors R1 and R2, a minute reference voltage is generated. The resistance division circuit is constructed so that it can be connected / disconnected by means of a switch consisting of a transistor Q3. Between a connection point P for the resistors R1 and R2 and a reference voltage output terminal, a switch constructed of a transistor Q4 is arranged, and a capacitor C is connected to the output terminal. The transistors Q3 and Q4 are controlled to be turned on / off by a clock pulse outputted by a control circuit 16. The capacitor C is charged to reference voltage when it is turned on, and the output terminal is kept at the reference voltage when it is turned off.

Description

technical field [0001] The present invention relates to a reference voltage generating circuit and a reference current generating circuit that generate a voltage or current used as a reference in the operation of other circuits, and more particularly to a circuit that generates a small reference voltage or a small reference current with low power consumption. Background technique [0002] figure 2 It is a circuit diagram of a conventional circuit configuration that generates a predetermined current (reference current) used as a reference in the operation of an electronic circuit. The circuit is integrated and formed on a semiconductor substrate. This circuit is configured to include a current mirror circuit 2 that generates a reference current from a reference voltage Vref, and an operational amplifier A provided to change impedance between a supply source of Vref and the current mirror circuit 2 . As the operating power supply for the current mirror circuit 2 and the oper...

AI Technical Summary

Problems solved by technology

Therefore, when the reference resistance Rref is increased in order to generate a small reference current Iref, the resistive element formed of polysilicon occupies a large area on the semiconductor substrate, and there is a problem of causing an increase in chip size or cost.

[0010] In addition, when a new reference voltage of a small voltage is generated by the resistor divider circuit, there is a problem that the power consumption becomes large by the amount of current flowing through the resistor divider circuit.

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