Ultra-low voltage CMOS threshold band-gap reference circuit

Abstract

The invention discloses an ultra-low voltage CMOS threshold bandgap reference circuit, which includes a PTAT generating circuit, a threshold voltage generating circuit and a starting circuit; the PTAT generating circuit includes three PMOS transistors MP2, MP3, and MP4, and two PNP transistors Q1 and Q2 Type bipolar transistor, OP1 an operational amplifier and two resistors R1, R2; the threshold voltage generation circuit includes four PMOS transistors MP5, MP6, MP7 and MP8, four NMOS transistors MN1, MN2, MN3 and MN4, OP2 An operational amplifier, R3 and a resistor; the startup circuit includes two PMOS transistors, MP1 and MP9. Compared with the traditional bandgap reference source, the output reference source in the present invention can work under ultra-low voltage conditions, thereby meeting the design requirements of low power consumption. At the same time, the circuit has a controllable output voltage, and compared with the traditional high-order compensation As for the bandgap reference source, the reference source realized by the present invention has a lower temperature drift coefficient, no special process requirements, and a simple structure.

Description

technical field [0001] The invention relates to an ultra-low voltage bandgap reference circuit, in particular to an ultra-low voltage CMOS threshold bandgap reference circuit, which belongs to the technical field of analog integrated circuits. Background technique [0002] The bandgap reference is an important circuit unit, which is widely used in the field of analog and hybrid integrated circuit design, such as ADC converters, DC / DC converters and power amplifiers. Its role is to provide the system with A stable DC voltage or current that is independent of supply voltage and temperature variations. In precision measuring instruments and widely used digital communication systems, reference voltage sources are often used as a reference for system measurement and calibration. Therefore, the reference voltage source occupies a very important position in the analog integrated circuit, which directly affects the performance and precision of the electronic system. Traditional ba...

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Problems solved by technology

Traditional bandgap voltage references such as figure 1 As shown, its disadvantage is mainly that the output voltage is maintained at about 1.25V, which limits low-voltage operation, and the temperature coefficient is also relatively large.

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