Reference voltage generation circuit with temperature compensating function

Abstract

A reference voltage generation circuit with a temperature compensating function relates to the reference voltage source technical field; the reference voltage generation circuit comprises a positive temperature coefficient voltage generation circuit and a similar LDO circuit connected in sequence; the positive temperature coefficient voltage generation circuit comprises single-stage or multistage unit circuits, wherein each stage unit circuit comprises a bias current source P using a MOS pipe and two NMOS pipes; unit circuits of various stages are cascaded in sequence; the grid electrode of NMOS pipe A and the grid electrode of NMOS pipe B in each stage unit circuit are connected, and respectively connected with the drain electrode of the NMOS pipe A and the drain electrode of the bias current source P; the source electrode of the NMOS pipe A and the drain electrode of the NMOS pipe B are connected to serve as an output node; the current generated by the bias current source P passes the NMOS pipe A and NMOS pipe B of the same stage, and is connected the source electrode of the NMOS pipe A and drain electrode of the NMOS pipe B of the next stage unit circuit through the source electrode of the NMOS pipe B of the previous stage; the similar LDO circuit comprises an operational amplifier and an output unit; the reference voltage generation circuit can effectively reduce system power consumption without obviously increasing area, and has the temperature compensating function.

Description

technical field [0001] The invention relates to the technical field of reference voltage sources, in particular to a reference voltage generation circuit with temperature compensation function. Background technique [0002] The voltage reference source is one of the indispensable components in many circuit systems. It is often used to provide a low temperature coefficient reference voltage for high-performance analog circuits or digital circuit modules to improve the performance of the circuit. [0003] In the prior art, in the field of integrated circuits, traditional voltage reference source circuits usually use a bandgap reference circuit composed of classic bipolar transistors. The basic principle is that the base-emitter junction of bipolar crystals has negative temperature characteristics ; On the other hand, when the collector currents of bipolar transistors are different, the temperature curves of the base-emitter junctions are different. When different currents flow...

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Problems solved by technology

[0004] However, the traditional bandgap reference circuit composed of bipolar transistors is not suitable for low-power design

The reasons are as follows: firstly, the BETA value of the current amplification factor of the traditional bipolar transistor is not constant. For hours, the BETA values ​​of two bipolar transistors biased with different currents may be significantly different, making the matching very poor; secondly, the bandgap reference circuit composed of traditional bipolar transistors usually uses arithmetic The amplifier takes out the difference ΔVBE of the junction voltage and puts it at both ends of the sampling resistor, and the current flowing through the sampling resistor also constitutes the static current in the bandgap reference circuit, so in low power consumption design, it is necessary to obtain a very small Static current, it is necessary to use a very large sampling resistance value and a larger resistance value of the amplifying resistance, which occupies a huge area and increases the influence of mining process gradient and stress; thirdly, the traditional bandgap reference circuit can only Generate a voltage of about 1.25V, which does not meet the needs of actual use

[0005] For the above reasons, the use of the traditional bandgap reference circuit has to be abandoned in the existing low-power design, and sometimes even a voltage reference source without temperature compensation has to be used, which affects the performance of the subsequent circuit. Increased the design difficulty of the subsequent stage circuit

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