A simple low-power low temperature drift voltage reference source

Abstract

The application provides a simple low-power low-temperature drift voltage reference source applied to the technical field of voltage reference sources, comprising an amplification circuit for amplifying the base voltage difference of a triode one Q1 and a triode two Q2; a feedback circuit for providing positive feedback coefficients and negative feedback coefficients respectively; a compensation module for compensating the negative feedback loop, expanding the bandwidth of the negative feedback loop, and improving the circuit stability; a current source I1 for providing biasing current for a triode three Q3, a resistor one R1 and a resistor two R2, so that the triode one Q1 and the triode two Q2 generate base voltages, wherein the anode of the current source I1 is connected with an input voltage VCC, and the cathode is connected with the output end of a reference voltage V VREF The amplification circuit is connected with the feedback circuit, and the feedback circuit is connected with the compensation module and the output end of the reference voltage respectively. The voltage reference source with low power consumption and low temperature coefficient can be obtained through a simple circuit structure.

Description

Technical Field

[0001] This invention belongs to the field of voltage reference source technology, specifically relating to a simple, low-power, low-temperature drift voltage reference source. Background Technology

[0002] Numerical control voltage references are a crucial component of modern analog integrated circuits. They provide reference voltages for series-type voltage regulator circuits, A / D and D / A converters, and serve as the regulated power supply or excitation source for most sensors. Additionally, voltage references can also function as standard batteries, calibration standards for instrument meters, and precision current sources.

[0003] Currently, with the increasing integration and precision of integrated circuits, it is necessary to provide high-precision performance indicators while meeting the requirements of harsh external environments. This necessitates the provision of high-precision voltage and current references within the chip. Invention patent 202211074702.5 provides a voltage reference source, including a startup circuit, a curvature correction circuit, an operational amplifier circuit, a negative feedback circuit, and a proportional resistor output circuit. The curvature correction circuit of this voltage reference source compensates for the negative temperature coefficient of the saturation voltage drop of the internal target transistor through the differential design of internal resistors with different positive temperature coefficients, obtaining a reference voltage with zero temperature coefficient at the base of the target transistor. It corrects the first-order and higher-order temperature curvature of the reference voltage or reference voltage using only the differences in temperature coefficients between multiple resistors. The principle is simple and easy to implement, the overall circuit structure is simple, and it outputs a low-temperature-drift reference voltage while being low in cost and power consumption.

[0004] This invention aims to provide a voltage reference source that, compared to the aforementioned patents, has a simpler circuit structure, lower production costs, and better output performance. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a simple, low-power, low-temperature drift voltage reference source that can obtain a voltage reference source with low power consumption and low temperature coefficient through a simple circuit structure.

[0006] A simple, low-power, low-temperature drift voltage reference source includes: an amplifier circuit for amplifying the base voltage difference between transistor Q1 and transistor Q2, wherein the amplifier circuit includes MOSFET MP1, MOSFET MP2, transistor Q1, transistor Q2, and resistor R3.

[0007] The feedback circuit includes a positive feedback loop and a negative feedback loop, which provide positive feedback coefficients and negative feedback coefficients respectively. The feedback circuit includes a MOSFET MP3, a resistor R1, and a resistor R2.

[0008] The compensation module is used to compensate the negative feedback loop, expand the bandwidth of the negative feedback loop, and improve the circuit stability. The compensation module includes a capacitor C1 and a resistor R4.

[0009] Current source I1 provides bias current to transistor Q3, resistor R1, and resistor R2, causing transistors Q1 and Q2 to generate base voltages. The positive terminal of current source I1 is connected to the input voltage VCC, and the negative terminal is connected to the reference voltage V. VREF Connect the output terminal;

[0010] The amplifier circuit is connected to the feedback circuit, and the feedback circuit is connected to the compensation module and the reference voltage V, respectively. VREF Connect the output terminal.

[0011] To form positive and negative feedback loops, the source of MOSFET MP3 is connected to the input voltage VCC, the gate of MOSFET MP3 is connected to the drain of MOSFET MP2 and the collector of transistor Q2, the drain of MOSFET MP3 is connected to a series of resistors R2, R1 and transistor Q3, the resistor R1 is connected to the base and collector of transistor Q3, and the emitter of transistor is grounded.

[0012] In order to form an amplifier circuit, the source of MOSFET MP1 and the source of MOSFET MP2 are both connected to the input voltage VCC, and the drain of MOSFET MP1 is connected to the gate of MOSFET MP1, the gate of MOSFET MP2, and the collector of transistor Q1, respectively.

[0013] The emitter of transistor Q1 is connected to the emitter of resistor R3 and transistor Q2 respectively. The other end of resistor R3 is grounded. The base of transistor Q1 is connected to the circuit between resistor R1 and resistor R2.

[0014] The base of transistor Q2 is connected to the circuit between resistor R1 and the collector of transistor Q3, and the collector of transistor Q2 is connected to the drain of MOSFET MP2.

[0015] To perform Miller compensation on the negative feedback loop, broaden the bandwidth, and improve stability, a capacitor C1 and a resistor R4 are connected in series between the gate and drain of the MOS transistor MP3.

[0016] To improve the stability of the output voltage, the reference voltage V VREF The output terminal is located in the circuit between resistor R4 and resistor R2, and the reference voltage V VREF The output terminal is also connected to capacitor C2, and the other end of capacitor C2 is grounded.

[0017] The beneficial effects of this invention are as follows: This simple, low-power, low-temperature-drift voltage reference source has a simple circuit structure. Transistors Q1 and Q2 not only generate temperature coefficients but also function as the input differential pair transistors of an amplifier. The base voltage difference between transistors Q1 and Q2 serves as the input voltage difference for the differential pair, reducing the number of amplifier components and greatly simplifying the circuit, thus lowering production costs. Furthermore, by employing temperature correction technology, a zero-temperature-coefficient voltage is generated through the interaction of positive and negative temperature coefficient voltages, enabling the circuit to output a stable reference voltage V. VREF This voltage reference source has the advantages of low power consumption and a small temperature coefficient. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is the circuit diagram of the present invention;

[0020] Figure 2 The reference voltage V of this invention VREF Simulation graph of temperature coefficient;

[0021] Figure 3 The static current I of this invention Q The simulation diagram. Detailed Implementation

[0022] Example 1

[0023] like Figure 1 As shown, a simple, low-power, low-temperature drift voltage reference source includes an amplifier circuit, a feedback circuit, a compensation module, and a current source I1; the amplifier circuit is connected to the feedback circuit, and the feedback circuit is connected to the compensation module and the reference voltage V. VREF Connect the output terminal.

[0024] In this configuration, the positive terminal of current source I1 is connected to the input voltage VCC, and the negative terminal is connected to the reference voltage V. VREF The output terminal is connected; the current source I1 is used to provide bias current for transistor Q3, resistor R1 and resistor R2, so that transistor Q1 and transistor Q2 generate base voltage.

[0025] like Figure 1As shown, the amplifier circuit includes MOSFET MP1, MOSFET MP2, transistor Q1, transistor Q2, and resistor R3. The amplifier circuit is used to amplify the base voltage difference between transistors Q1 and Q2. Since transistors Q1 and Q2 are the differential pair of the amplifier, the base voltage difference between transistors Q1 and Q2 is the input voltage difference of the differential pair.

[0026] Specifically, the source of MOSFET MP1 and the source of MOSFET MP2 are both connected to the input voltage VCC, and the drain of MOSFET MP1 is connected to the gate of MOSFET MP1, the gate of MOSFET MP2, and the collector of transistor Q1.

[0027] The emitter of transistor Q1 is connected to the emitter of resistor R3 and transistor Q2 respectively. The other end of resistor R3 is grounded. The base of transistor Q1 is connected to the circuit between resistor R1 and resistor R2.

[0028] The base of transistor Q2 is connected to the circuit between resistor R1 and the collector of transistor Q3, and the collector of transistor Q2 is connected to the drain of MOSFET MP2.

[0029] like Figure 1 As shown, the feedback circuit includes MOSFET MP3, resistor R1, and resistor R2, which are used to provide positive and negative feedback coefficients.

[0030] Specifically, the source of MOSFET MP3 is connected to the input voltage VCC, the gate of MOSFET MP3 is connected to the drain of MOSFET MP2 and the collector of transistor Q2, and the drain of MOSFET MP3 is connected in series with resistors R2 and R1 and transistor Q3. Resistor R1 is connected to the base and collector of transistor Q3, and the emitter of transistor Q3 is grounded.

[0031] Furthermore, for the amplifier circuit composed of MOSFET MP1, MOSFET MP2, transistor Q1, transistor Q2, and resistor R3, MOSFET MP3, resistor R2, and the amplifier circuit form a negative feedback loop, where the negative feedback coefficient is:

[0032]

[0033] The MOSFET MP3, resistors R1 and R2, and the amplifier circuit form a positive feedback loop, where the positive feedback coefficient is:

[0034]

[0035] in, It is the transconductance of transistor Q3.

[0036] via β N and β P From the expression, we can know that β N >β P That is, the negative feedback coefficient is greater than the positive feedback coefficient, so as to ensure the stability of the circuit.

[0037] like Figure 1 As shown, the compensation module includes capacitor C1 and resistor R4. The gate and drain of MOSFET MP3 are connected in series with capacitor C1 and resistor R4. The compensation module is used to compensate the negative feedback loop, expand the bandwidth of the negative feedback loop, and improve the circuit stability.

[0038] Reference voltage V VREF The output terminal is located in the circuit between resistor R4 and resistor R2, with a reference voltage V. VREF The output terminal is also connected to capacitor C2, with the other end of capacitor C2 grounded. Capacitor C2 is used to increase the output reference voltage V. VREF Stability.

[0039] A stable reference voltage V is generated through temperature correction. VREF The process is as follows:

[0040] The positive temperature coefficient current generated by transistors Q1 and Q2 and resistor R1 is: The junction voltage V between the base and emitter of transistor Q3 BE The transistors Q2 and Q3 generate a negative temperature coefficient voltage, while the resistor R3 generates a positive temperature coefficient current. Then the reference voltage V can be obtained. VREF The expression is as follows:

[0041]

[0042] Simplified, we can obtain

[0043]

[0044] Where, ΔV BE1 =V BEQ1 -V BEQ2 ΔV BE2 =V BEQ3 -V BEQ2 ΔV BE1 ΔV BE2 Given a positive temperature coefficient voltage, the current amplification factor β of transistor Q1 is... F It has a negative temperature coefficient, and the temperature coefficients of resistors R1, R2, and R3 are the same.

[0045] Therefore, by adjusting the ratio of resistor R1 and resistor R2, it is possible to achieve... A offset V BE The linear term in; ΔV BE2 and β F The temperature coefficients are different, so the temperature coefficients are set to K respectively. V and K β At temperature T = T0, Performing Taylor expansion yields the following expression:

[0046]

[0047] Simplified, we get:

[0048]

[0049] Therefore, by appropriately adjusting the ratio between resistor R2 and resistor R3, and the temperature coefficient K... V and K β V can be further offset by the linear terms and first-order, second-order, and other higher-order terms in formula (4). BE The remaining higher-order terms in the equation make the reference voltage V VREF The temperature coefficient has been further corrected, resulting in a more stable output.

[0050] like Figure 2 As shown, the corrected reference voltage V VREF The temperature coefficient curve shows that the temperature coefficient is only 2.2 ppm / ℃ when the temperature changes from -40℃ to 150℃. Meanwhile, as... Figure 3 As shown, when the temperature changes from -40℃ to 150℃, the quiescent current I of the circuit... Q The static current I changes from 3.4uA to 6.3uA. Q The lower power consumption significantly reduces the system power consumption of this circuit.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A simple, low-power, low-temperature drift voltage reference source, characterized in that, include: An amplifier circuit is used to amplify the base voltage difference between transistor Q1 and transistor Q2. The amplifier circuit includes MOSFET MP1, MOSFET MP2, transistor Q1, transistor Q2, and resistor R3. The source of MOSFET MP1 and the source of MOSFET MP2 are both connected to the input voltage VCC. The drain of MOSFET MP1 is connected to the gate of MOSFET MP1, the gate of MOSFET MP2, and the collector of transistor Q1, respectively. The emitter of transistor Q1 is connected to one end of resistor R3 and the emitter of transistor Q2, respectively. The other end of resistor R3 is grounded. The base of transistor Q1 is connected to the circuit between resistor R1 and resistor R2. The base of transistor Q2 is connected to the circuit between resistor R1 and the collector of transistor Q3, and the collector of transistor Q2 is connected to the drain of MOSFET MP2. The feedback circuit includes a positive feedback loop and a negative feedback loop, providing positive and negative feedback coefficients respectively. The feedback circuit includes a MOSFET MP3, a resistor R1, and a resistor R2. The source of the MOSFET MP3 is connected to the input voltage VCC. The gate of the MOSFET MP3 is connected to the drain of the MOSFET MP2 and the collector of the transistor Q2. The drain of the MOSFET MP3 is connected to a series of resistors R2, R1, and the transistor Q3. The resistor R1 is connected to the base and collector of the transistor Q3. The emitter of the transistor Q3 is grounded. The compensation module is used to compensate the negative feedback loop, expand the bandwidth of the negative feedback loop, and improve the circuit stability. The compensation module includes a capacitor C1 and a resistor R4. Current source I1 provides bias current to transistor Q3, resistor R1, and resistor R2, causing transistors Q1 and Q2 to generate base voltages. The positive terminal of current source I1 is connected to the input voltage VCC, and the negative terminal is connected to the reference voltage. Connect the output terminal; The amplifier circuit is connected to the feedback circuit, and the feedback circuit is connected to the compensation module and the reference voltage, respectively. Connect the output terminal.

2. The simple, low-power, low-temperature drift voltage reference source according to claim 1, characterized in that, The gate and drain of the MOS transistor MP3 are connected in series with a capacitor C1 and a resistor R4.

3. The simple, low-power, low-temperature drift voltage reference source according to claim 1, characterized in that, The reference voltage The output terminal is located in the circuit between resistor R4 and resistor R2, and the reference voltage The output terminal is also connected to capacitor C2, and the other end of capacitor C2 is grounded.

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