Improved band-gap reference voltage source and band-gap reference voltage generating circuit

Abstract

The invention provides an improved band-gap reference voltage source and a band-gap reference voltage generating circuit. The band-gap reference voltage generating circuit comprises the improved band-gap reference voltage source and a cascade current mirror circuit. The band-gap reference voltage generating circuit feeds current back to the positive power supply input end of the improved band-gap reference voltage source through the cascade current mirror circuit. Simultaneously, in the improved band-gap reference voltage source, a P type metal-oxide-semiconductor field-effect transistor (MOSFET) is arranged between a power supply end and the conventional improved band-gap reference voltage source, so that the impedance of the power supply input end is approximately the transimpedance of the MOSFET and the power supply suppression ratio of the power supply is increased. Moreover, two resistors are arranged in the improved band-gap reference voltage source on the basis of the conventional improved band-gap reference voltage source, so that drain end voltage of two groups of symmetrical tubes of a differential circuit is closer to each other and current is better matched simultaneously.

Description

Technical field [0001] The invention relates to a bandgap reference voltage source and a bandgap reference voltage generating circuit, in particular to an improved bandgap reference voltage source and a bandgap reference voltage generating circuit with high power supply rejection ratio and better matching of MOS differential pair tube currents Circuit. Background technique [0002] Because of its low temperature coefficient characteristics, the band gap reference voltage source is widely used in various analog and mixed signal circuit systems. Accordingly, the band gap reference voltage has become an indispensable part of analog and mixed signal circuit systems. figure 1 It is a circuit structure diagram of a traditional bandgap reference voltage generating circuit. As shown in the figure, the conventional bandgap reference voltage generating circuit includes a conventional bandgap reference voltage source 101 and a regulator 102, where the conventional bandgap reference voltage ...

AI Technical Summary

Problems solved by technology

[0003] Although the traditional bandgap reference voltage generation circuit can obtain a relatively high power supply rejection ratio by adding a regulator, the circuit has the following disadvantages: 1. The drain voltages of the PMOS transistors M3 and M4, and the NMOS transistors M1 and M2 are inconsistent It will cause the currents passing through them to not be completely matched; 2. The added regulator 103 will introduce a voltage offset of the circuit, which increases the difficulty of design

[0004] To sum up, it can be seen that the bandgap reference voltage generating circuit of the prior art has the problems that the currents flowing through each transistor cannot be completely matched and the voltage offset will be generated. Therefore, it is necessary to propose an improved technical means to solve this problem. a question

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