Current reference source circuit and method for generating current reference source

Abstract

The invention relates to an integrated circuit and discloses a current reference source circuit and a method for generating a current reference source. The method comprises the following steps of: generating a linear positive temperature coefficient current, a nonlinear negative temperature coefficient current and a nonlinear positive temperature coefficient current through three circuits respectively; superimposing the three currents; and taking the superimposed output currents as the current reference source. The linear positive temperature coefficient current is used for effectively offsetting linear components in the nonlinear negative temperature coefficient current, and the nonlinear positive temperature coefficient current is used for compensating residual nonlinear negative temperature coefficients, so that the sensitivity of the acquired currents to temperature changes is further reduced, and the current reference source which approximates to a zero temperature coefficient can be realized.

Description

technical field [0001] The present invention relates to integrated circuits, in particular to current reference sources in integrated circuits. Background technique [0002] The current reference source circuit is widely used in integrated circuit design, and is one of the basic module circuits in the design of analog integrated circuits and digital-analog hybrid integrated circuits. The main application of the current reference source circuit in the analog circuit is to provide a stable reference current for other circuits or system modules. Therefore, the accuracy and characteristics of the current generated by the current reference source circuit will directly affect the performance of other module circuits in the circuit. [0003] In order to obtain a high-precision current reference source, the existing high-performance current reference source generation circuit mainly generates a reference voltage with zero temperature coefficient based on the voltage reference circu...

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Problems solved by technology

[0007] However, if bipolar transistors are used for high-order compensation, the use of this circuit will be limited by the process

Because the collector of the PNP transistor provided by the traditional complementary metal-oxide semiconductor (Complementary Metal-Oxide Semiconductor, "CMOS") process can only be connected to the lowest potential, therefore, the implementation of the current reference source circuit using the BiCMOS process will increase the cost; at the same time, the triode temperature compensation structure is replaced by a metal-oxide-semiconductor (Metal-Oxide-Semiconductor, referred to as "MOS") tube compensation structure. Although it is compatible with the CMOS process, the MOS tube in the compensation circuit works at the subthreshold area, which requires the MOS tube to have a large area, but the temperature characteristics of the subthreshold region of the MOS tube VGS will be affected by the current, and the performance characteristics will change. Therefore, this compensation structure not only increases the area, but also has a low temperature compensation effect. too ideal

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