Band-gap reference circuit with second-order curvature compensation

Abstract

The invention discloses a band-gap reference circuit with second-order curvature compensation, which counteracts a second-order item in VBE through approximate voltage replication, so that the temperature drift of band-gap voltage is lower. The conversion circuit comprises a starting circuit module, a PTAT current generation module, a CTAT current generation module, an output module and a thermal turn-off module. The starting circuit module helps a circuit to be separated from a degenerate working point, and normal work of other modules is guaranteed; the PTAT current generation module and the CTAT current generation module generate positive temperature coefficient current and negative temperature coefficient current respectively and gather the positive temperature coefficient current and the negative temperature coefficient current to the output module, and meanwhile the CTAT current generation module counteracts a second-order term in VBE through approximate voltage copy. The output module generates different band-gap reference voltages by using resistance voltage division to supply power to the chip; the thermal turn-off module provides a hysteresis effect and protects the chip from an over-temperature phenomenon. The invention has the advantages of simple structure, low temperature drift, no operational amplifier and the like, and can be used for analog integrated circuits.

Description

technical field [0001] The invention belongs to the technical field of circuits, in particular to a bandgap reference circuit with second-order curvature compensation, which can be used for simulating integrated circuits. Background technique [0002] The bandgap reference module is a crucial module in the integrated circuit chip. The purpose of the bandgap reference module is to generate a DC voltage or current independent of power supply, process and operating temperature, which has been proved to be essential in many analog circuits. Less. Traditional bandgap references such as figure 1 shown. The basic principle is to use the appropriate weighted addition of two quantities with opposite temperature coefficients, and the result will show a zero temperature characteristic. Negative temperature coefficient voltage V BE , the positive temperature coefficient voltage ΔV BE . Its output voltage is: [0003] [0004] where, since V BE6 It has temperature nonlinearity...

AI Technical Summary

Problems solved by technology

[0005] The accuracy and temperature drift of the bandgap reference module directly affect the performance of the entire circuit to a large extent. However, the traditional bandgap is first-order temperature compensation. Considering the nonlinearity of the Vbe voltage, the temperature of the first-order temperature compensation reference The coefficient (TC) is always limited to 20 to 100ppm / ℃, which does not meet the high performance requirements of the chip

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