Zero temperature drift current source circuit insensitive to power supply

Abstract

A zero temperature drift current source circuit insensitive to a power supply comprises an NJFET, triodes of NPN1, NPN2, NPN3 and NPN4, triodes of PNP1, PNP2 and PNP3, and resistors of R1, R2 and R3,wherein when VCC rises from 2.5 voltages to 40 voltages, the starting current I0 of the NJFET is fixed and the resistor R1 is an adjustable positive temperature coefficient resistor, the product ratioof the numbers of emitter areas of NPN1 and NPN2 is A1, the product ratio of the numbers of emitter areas of NPN4 and NPN3 is A2, A1*A2 is larger than 1, and the temperature coefficient of R1 can beadjusted through process, the zero temperature drift current source circuit can be designed. The magnitude of the current source reference current IR is completely dependent on the resistance values of A1, A2 and R1, the current source reference current IR and the current source output current IOUT do not change with the change of VCC.

Description

technical field [0001] The invention relates to a current source circuit, in particular to a zero-temperature-drift current source circuit which is insensitive to a power supply, and belongs to the technical field of integrated circuits. Background technique [0002] The current current source circuit is generally a current bias circuit, but many of them rarely consider the power supply sensitivity, low temperature drift coefficient, and circuit reliability when designing the current bias circuit, and due to the lack of consideration of the above-mentioned aspects in the design process Due to the consideration of aspects, some performance of the current source circuit is often affected during use. For example, the startup part of many circuits uses a large resistor, so that the quiescent current will change with the change of VCC, and the large resistor is also a waste of layout area. . Contents of the invention [0003] The object of the present invention is to provide a...

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Problems solved by technology

[0002] The current current source circuit is generally a current bias circuit, but many of them rarely consider the power supply sensitivity, low temperature drift coefficient, and circuit reliability when designing the current bias circuit, and due to the lack of consideration of the above-mentioned aspects in the design process Due to the consideration of aspects, some performance of the current source circuit is often affected during use. For example, the startup part of many circuits uses a large resistor, so that the quiescent current will change with the change of VCC, and the large resistor is also a waste of layout area.

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