Integrated circuit and method for calibrating temperature drift of bandgap reference voltage using self-heating

Abstract

The invention discloses an integrated circuit and a method for calibrating temperature excursion of a voltage of a band-gap reference by using self-heating. The integrated circuit comprises the band-gap reference, an analog-to-digital converter, a first switch, a second switch, a third switch and a fourth switch, wherein the band-gap reference is connected with the analog-to-digital converter via the first and second switches; one end of the third switch and one end of the fourth switch are connected with the analog-to-digital converter, the other end of the third switch is connected with a VIP end, and the other end of the fourth switch is connected with a VIN end; the analog-to-digital converter is separately connected with triode junction voltage output VBE1 and VBE 2 in the band-gap reference via the first and second switches. In the integrated circuit provided by the invention, quick local heating is achieved by heating resistors arranged right above or around triodes Q1 and Q2 arranged in the band-gap reference; a junction voltage difference VBE1-VBE2 and a reference voltage VREF are simultaneously collected via the internal analog-to-digital converter and an external measurement instrument, so that measurement after heat balance is not needed, time required by measurement is greatly saved, and calibration cost is reduced.

Description

technical field [0001] The invention relates to a bandgap reference circuit, in particular to an integrated circuit for calibrating the temperature drift of the bandgap reference voltage by self-heating and its method. Background technique [0002] The bandgap reference circuit is a circuit used to generate a constant reference voltage, which provides high-precision reference voltages for other functional modules such as analog-to-digital converters and digital-to-analog converters inside the integrated circuit. The traditional bandgap reference circuit is implemented based on the junction voltage of the triode, and the generated reference voltage can be expressed by the following formula, namely: [0003] VREF=α*VBE+β*ΔVBE [0004] Among them, the junction voltage VBE of the triode is inversely proportional to the temperature, and the junction voltage difference ΔVBE is directly proportional to the temperature. By adjusting the α coefficient and the β coefficient, the posi...

AI Technical Summary

Problems solved by technology

Since the temperature coefficient of the junction voltage VBE of the triode has poor consistency between different batches of manufacturing, and the stress of the package will also change the temperature coefficient, therefore, if it is not calibrated, the temperature drift of the final reference voltage will will be big

[0005] The traditional temperature drift calibration method needs to collect voltage values ​​at multiple temperature points. At the same time, the temperature value of each temperature point must wait for thermal equilibrium to be measured, so the calibration time is very long and the cost is very high.

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