A current mirror circuit provided with a calibration circuit

A technology for calibrating circuits and current mirrors, applied in the direction of adjusting electrical variables, instruments, control/regulating systems, etc., can solve problems such as current mirror mismatch and process deviation, and achieve the effect of reducing mismatch and improving replication accuracy.
CN107817868BActive Publication Date: 2019-06-21NANJING ZGMICRO CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
NANJING ZGMICRO CO LTD
Publication Date
2019-06-21

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Abstract

The invention provides a current mirror circuit which comprises a first MOS tube, a second MOS tube, a first resistor, a second resistor, a first adjustable resistor, a second adjustable resistor, a switch circuit and a calibrating circuit. The calibrating circuit controls a first switch to be on first and then controls a second switch and a third switch to be off; at the moment, the calibrating circuit samples and compares the voltage at the other end of the first resistor with that of the other end of the second resistor; when the first sampling voltage is greater than the second sampling voltage, the calibrating circuit adjusts the first regulatable resistor to a first effective resistance value and controls the second switch of the switch circuit to be on and the first switch and the third switch to be off; when the first sampling voltage is lower than the second sampling voltage, the calibrating circuit adjusts the second adjustable resistor to a second effective resistance value,and controls the third switch of the switch circuit to be on and the first and second switches to be off. Compared with the prior art, mismatch of current copy of the current mirror can be reduced, and the copy precision of the current mirror can be increased.
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Description

[0001] 【Technical field】

[0002] The invention relates to the technical field of electronic circuits, in particular to a current mirror circuit provided with a calibration circuit.

[0003] 【Background technique】

[0004] Current mirrors are widely used in various analog circuits, for example, to generate current bias or as a load for operational amplifiers. However, due to process deviations, the output current is not equal to the input current, which is manifested as a mismatch of the current mirror.

[0005] Please refer to figure 1 As shown, it is a schematic circuit diagram of a current mirror in the prior art, which includes PMOS (positive channel Metal Oxide Semiconductor) transistors MP1 and MP2, and the input current source I1 can generate an output current Io through the current mirror. Due to process deviation, there is a mismatch between PMOS transistors MP1 and MP2 during mass production, so that the current value of the output current Io of some chips is greate...

Claims

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