CN108549454A - A kind of low-power consumption, high-precision reference voltage source - Google Patents

Abstract

The invention relates to the technical field of power supplies in analog circuits, in particular to a low-power, high-precision reference voltage source. A low-power, high-precision reference voltage source in the present invention includes a core circuit, a compensation circuit, and a superposition circuit; the core circuit generates a positive temperature coefficient current, the compensation circuit generates a positive temperature coefficient current, and the superposition A circuit superimposes the positive temperature coefficient current and the negative temperature coefficient current to generate a reference voltage VREF. The invention improves the traditional reference voltage generating circuit, and has lower power consumption and higher output precision.

Description

A low-power, high-accuracy reference voltage source

technical field

The invention relates to the technical field of power supplies in analog circuits, in particular to a low-power, high-precision reference voltage source.

Background technique

The reference voltage source is an important module in analog circuit design, mixed signal circuit design and digital design. It provides the system with a reference voltage that does not vary with temperature and supply voltage. In the reference voltage generation circuit, the two parameters of output accuracy and power consumption play a decisive role in the performance of the power supply. The reference voltage generation circuit with high precision, low power consumption, high power supply rejection ratio and low temperature coefficient is very important for the whole important for the circuit. A traditional bandgap reference source can obtain a reference voltage with zero temperature coefficient by linearly superimposing two voltages with positive and negative temperature coefficients. The difference between the base-emitter voltages of two bipolar transistors is proportional to the absolute temperature. The base-emitter voltage of bipolar transistors has a negative temperature coefficient. A certain ratio results in a reference voltage that is independent of temperature changes. However, because the traditional reference voltage generation circuit only performs linear compensation, the accuracy is poor, and the generated voltage is usually not ideal when the temperature range changes greatly, especially in some circuits that require relatively high voltage accuracy. After linear compensation The generated voltage is far from meeting the requirements. Some of the improved reference voltage sources mostly adopt the method of adding feedback loop or high-order curvature compensation circuit, etc., the circuit structure is relatively complicated, and the power consumption is high. Based on this, the present invention provides a reference voltage source.

Contents of the invention

The object of the present invention is to provide a reference voltage source with higher stability and lower power consumption in order to solve the problems of poor stability and high power consumption of the reference voltage source in the prior art.

The present invention provides a low-power, high-precision reference voltage source, including a core circuit, a compensation circuit and a superposition circuit; the core circuit generates a positive temperature coefficient current, the compensation circuit generates a positive temperature coefficient current, and the superposition A circuit superimposes the positive temperature coefficient current and the negative temperature coefficient current to generate a reference voltage VREF. The core circuit includes: MOS transistors M1, M2, M3, M4, operational amplifier OP1, resistor R1, transistors Q1, Q2; the compensation circuit includes: MOS transistors M5, M6, M7, M8, M9, M11, M12, Resistor R2 and transistor Q3; the superposition circuit includes MOS transistors M10 and resistor R3; the sources of the MOS transistors M1, M3, M5, M7, M9, and M10 are all connected to the power supply voltage, and the MOS transistors M1, M3, M5 The gates of M7 and M7 are all connected and connected to the output terminal of the operational amplifier OP1, the gates of the MOS transistors M2, M4, M6, and M8 are all connected; the source of the MOS transistor M2 is connected to the drain of the MOS transistor M1, and the drain The pole is connected to the non-inverting input terminal of the operational amplifier OP1 and one end of the resistor R1, and the other end of the resistor R1 is connected to the emitter of the triode Q1; the source of the MOS transistor M4 is connected to the drain of the MOS transistor M2, and the drain is connected to the operational amplifier OP1 The inverting input terminal of the triode and the emitter of the transistor Q2, the bases of the transistors Q1 and Q2 are connected and grounded, and the collectors of both are grounded; the source of the MOS transistor M6 is connected to the drain of the MOS transistor M5, and the drain is connected to The drain and gate of the MOS transistor M11 and the gate of the MOS transistor M12, the source of the MOS transistor M12 are connected to the emitter of the transistor Q3, the base and the collector of the transistor Q3 are grounded, and the source of the MOS transistor M12 passes through the resistor R2 Grounding; the source of the MOS transistor M8 is connected to the drain of the MOS transistor M7, and the drain is connected to the reference voltage output terminal VREF; the gates of the MOS transistors M9 and M10 are connected and connected to the drain of the MOS transistor M9 and the MOS transistor M12 The drain of the MOS transistor M10 is grounded through the resistor R3, and the drain terminal of the MOS transistor is the reference voltage output terminal VREF; the MOS transistors M1, M2, M3, M4, M5, M6, M7, M8, and M9 are all It is a PMOS transistor, and the MOS transistors M11 and M12 are both NMOS transistors.

A low-power, high-precision reference voltage source provided by the present invention effectively solves the problems of poor stability and high power consumption of the reference voltage source in the prior art. Compared with the traditional reference voltage source circuit, the above reference The voltage source circuit has high output stability and precision, and compared with the existing improved circuit structure, the above circuit has a simple structure, uses less operational amplifiers, and saves power consumption.

Description of drawings

FIG. 1 is a schematic structural diagram of a low-power, high-precision reference voltage source circuit provided by the present invention.

FIG. 2 is a simulation structure diagram of the output voltage of the reference voltage source circuit provided by the present invention.

Detailed ways

The present invention provides a low-power, high-precision reference voltage source. In order to make the purpose, technical solution and advantages of the present invention clearer and clearer, the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Figure 1, a low-power, high-precision reference voltage source includes a core circuit, a compensation circuit, and a superposition circuit; the core circuit generates a positive temperature coefficient current, and the compensation circuit generates a positive temperature coefficient current, so The superposition circuit superimposes the positive temperature coefficient current and the negative temperature coefficient current to generate a reference voltage VREF. The core circuit includes: MOS transistors M1, M2, M3, M4, operational amplifier OP1, resistor R1, transistors Q1, Q2; the compensation circuit includes: MOS transistors M5, M6, M7, M8, M9, M11, M12, Resistor R2 and transistor Q3; the superposition circuit includes MOS transistors M10 and resistor R3; the sources of the MOS transistors M1, M3, M5, M7, M9, and M10 are all connected to the power supply voltage, and the MOS transistors M1, M3, M5 The gates of M7 and M7 are all connected and connected to the output terminal of the operational amplifier OP1, the gates of the MOS transistors M2, M4, M6, and M8 are all connected; the source of the MOS transistor M2 is connected to the drain of the MOS transistor M1, and the drain The pole is connected to the non-inverting input terminal of the operational amplifier OP1 and one end of the resistor R1, and the other end of the resistor R1 is connected to the emitter of the triode Q1; the source of the MOS transistor M4 is connected to the drain of the MOS transistor M2, and the drain is connected to the operational amplifier OP1 The inverting input terminal of the triode and the emitter of the transistor Q2, the bases of the transistors Q1 and Q2 are connected and grounded, and the collectors of both are grounded; the source of the MOS transistor M6 is connected to the drain of the MOS transistor M5, and the drain is connected to The drain and gate of the MOS transistor M11 and the gate of the MOS transistor M12, the source of the MOS transistor M12 are connected to the emitter of the transistor Q3, the base and the collector of the transistor Q3 are grounded, and the source of the MOS transistor M12 passes through the resistor R2 Grounding; the source of the MOS transistor M8 is connected to the drain of the MOS transistor M7, and the drain is connected to the reference voltage output terminal VREF; the gates of the MOS transistors M9 and M10 are connected and connected to the drain of the MOS transistor M9 and the MOS transistor M12 The drain of the MOS transistor M10 is grounded through the resistor R3, and the drain terminal of the MOS transistor is the reference voltage output terminal VREF; the MOS transistors M1, M2, M3, M4, M5, M6, M7, M8, and M9 are all It is a PMOS transistor, and the MOS transistors M11 and M12 are both NMOS transistors.

In the above-mentioned reference voltage source circuit, the bias current flowing through the resistor R1 is generated through the current mirror effect, and the drain current flowing through the MOS transistor M8 is a positive temperature coefficient current, and the current flowing through the source terminal of the MOS transistor M11 is VBE3 /R2, so that the current flowing through the source terminal of the MOS tube M12 is a negative temperature coefficient current, and the current flowing through the drain terminal of the MOS tube M10 is also a negative temperature coefficient current after current mirroring, so that it can be superimposed by adjusting the parameters of the components The zero temperature coefficient reference voltage VREF. Fig. 2 is the simulation result graph of the output voltage when the power supply voltage is 2.6V, 3.3V, 4V respectively. Compared with the traditional reference voltage source circuit, the above-mentioned reference voltage source circuit has higher output stability and precision, and compared with the existing improved circuit structure, the above-mentioned circuit has a simple structure, uses less operational amplifiers, and saves power consumption.

It should be understood that the application of the present invention is not limited to the above examples, and those skilled in the art can make improvements or transformations according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (2)

1. a kind of low-power consumption, high-precision reference voltage source, which is characterized in that including core circuit, compensation circuit and superposition electricity Road；The core circuit generates positive temperature coefficient electric current, and the compensation circuit generates positive temperature coefficient electric current, the supercircuit The positive temperature coefficient electric current and negative temperature parameter current are superimposed and generate reference voltage V REF.

2. a kind of reference voltage source as described in claim 1, which is characterized in that the core circuit includes：Metal-oxide-semiconductor M1, M2, M3, M4, operational amplifier OP1, resistance R1, triode Q1, Q2；The compensation circuit includes：Metal-oxide-semiconductor M5, M6, M7, M8, M9, M11, M12, resistance R2 and triode Q3；The supercircuit includes metal-oxide-semiconductor M10 and resistance R3；The metal-oxide-semiconductor M1, M3, M5, The source electrode of M7, M9, M10 are all connected with supply voltage, and the grid of described metal-oxide-semiconductor M1, M3, M5, M7 are connected and connect operation amplifier The grid of the output end of device OP1, described metal-oxide-semiconductor M2, M4, M6, M8 is connected；The source electrode connection metal-oxide-semiconductor M1's of the metal-oxide-semiconductor M2 Drain electrode, the normal phase input end of drain electrode connection operational amplifier OP1 and one end of resistance R1, the other end of resistance R1 connect three poles The emitter of pipe Q1；The drain electrode of the source electrode connection metal-oxide-semiconductor M2 of the metal-oxide-semiconductor M4, the reverse phase of drain electrode connection operational amplifier OP1 are defeated Enter the emitter of end and triode Q2, the base stage of triode Q1, Q2 are connected and are grounded, and the collector of the two is grounded；It is described The drain electrode of the source electrode connection metal-oxide-semiconductor M5 of metal-oxide-semiconductor M6, the drain electrode of drain electrode connection metal-oxide-semiconductor M11, the grid of grid and metal-oxide-semiconductor M12, The emitter of the source electrode connecting triode Q3 of metal-oxide-semiconductor M12, the base stage and collector of triode Q3 are grounded, the source of metal-oxide-semiconductor M12 Pole is grounded by resistance R2；The drain electrode of the source electrode connection metal-oxide-semiconductor M7 of the metal-oxide-semiconductor M8, drain electrode connection reference voltage output end VREF；The grid of described metal-oxide-semiconductor M9, M10 are connected and connect the drain electrode of the drain electrode and metal-oxide-semiconductor M12 of metal-oxide-semiconductor M9, metal-oxide-semiconductor M10's Drain electrode is grounded by resistance R3, and the drain electrode end of metal-oxide-semiconductor is reference voltage output end VREF；The metal-oxide-semiconductor M1, M2, M3, M4, M5, M6, M7, M8, M9 are PMOS tube, and described metal-oxide-semiconductor M11, M12 are NMOS tube.