Voltage reference source temperature drift correction module and method

Abstract

The invention provides a voltage reference source temperature drift correction module and method, the module comprises a power supply unit, a voltage reference source and a voltage division unit controlled by temperature, the power supply unit is connected with the voltage reference source and is configured to provide bias voltage for the voltage reference source, the voltage reference source comprises three pins, one pin is grounded, and the other pin is grounded. The other two pins are connected, a connection node of the two connected pins is connected with the power supply unit, one end of the voltage dividing unit is connected with the connection node of the two connected pins, and the other end of the voltage dividing unit is grounded. According to the invention, few components are adopted to improve the high and low temperature deviation phenomenon of the voltage reference source, the temperature coefficient of the module power supply is effectively reduced, the problems of low or high output voltage and output overvoltage protection failure caused by the deviation of the voltage reference source at high and low temperatures are solved, and the reliability of the module power supply product is improved.

Description

Technical Field

[0001] The present application relates to the technical field of voltage reference source temperature drift, and in particular to a voltage reference source temperature drift correction module and method. Background Art

[0002] As an extremely important component of integrated circuits, the reference source circuit is used to output a stable, accurate power supply that does not drift greatly with temperature, does not fluctuate with changes in the subsequent load, and does not change over time. As one of the most important modules in integrated circuit systems, the reference source circuit has not only seen a steady increase in demand, but also puts forward higher requirements for its performance parameters and other indicators. However, in normal production and use, the normal operation of the circuit will generate a large amount of heat energy, causing the temperature of the chip and circuit board to rise, making the chip and circuit work abnormally, which is easy to cause serious errors such as calculation errors and confusion of logical values, and may even cause the chip to burn out, resulting in unpredictable losses.

[0003] The existing voltage reference source has poor temperature characteristics, which results in the power module performance not meeting the standards. There are mainly the following problems:

[0004] 1. The temperature coefficient is out of range.

[0005] 2. The output voltage is low at low temperature, the overvoltage protection value is reduced, and even the output cannot be normal.

[0006] 3. At high temperatures, the output overvoltage protection point increases, and the output overvoltage protection cannot be implemented normally, causing damage to internal components or damage to subsequent circuits.

[0007] How to reasonably and accurately control the generation of low temperature drift reference voltage is a difficult problem faced by technicians in this field. At present, most voltage reference temperature drift correction circuits use a large number of components for complex connections. Too many components increase the risk of circuit damage and the risk of being affected by temperature, which is not conducive to application in small-volume, device-intensive modules. Summary of the invention

[0008] In order to solve the above problems, the present application proposes a voltage reference source temperature drift correction module, which adopts a resistor voltage divider method and cleverly utilizes the temperature characteristics of the voltage reference source and thermistor to correct the reference voltage, thereby reducing the change of the reference voltage with temperature. It has the characteristics of simple design and easy adjustment, and is very suitable for application in module power supplies with small size and dense components.

[0009] This application is implemented through the following technical solutions:

[0010] The present application proposes a voltage reference source temperature drift correction module, comprising:

[0011] Power supply unit;

[0012] Voltage reference source;

[0013] Temperature controlled pressure dividing unit;

[0014] The power supply unit is connected to a voltage reference source and is configured to provide a bias voltage to the voltage reference source;

[0015] The voltage reference source includes three pins, one of which is grounded, the other two pins are connected, and the connection node of the two connected pins is connected to the power supply unit;

[0016] One end of the voltage dividing unit is connected to a connection node of two connected pins, and the other end of the voltage dividing unit is grounded.

[0017] Furthermore, the power supply unit includes a voltage-dividing resistor R2, one end of which is connected to a voltage-stabilizing power supply, and the other end of which is connected to a connection node of two connected pins of a voltage reference source.

[0018] Furthermore, the three pins of the voltage reference source are respectively pin 1, pin 2 and pin 3, the pin 1 is configured as an anode, the pin 2 is configured as a voltage output port, and the pin 3 is configured as a cathode.

[0019] Furthermore, the voltage divider unit includes a resistor R1 and a resistor RT, the resistor R1 and the resistor RT are connected in series, one end of the resistor R1 away from the resistor RT is connected to a connection node of two connected pins of a voltage reference source, one end of the resistor RT away from the resistor R1 is grounded, and the resistor RT is configured as a thermistor.

[0020] Furthermore, the resistor RT is a negative temperature coefficient resistor.

[0021] Furthermore, the connection node where the resistor R1 is connected to the resistor RT is an output node, and the calculation formula of the output voltage of the output node is:

[0022]

[0023] Among them, VREF is the output voltage of the output node, RT is the resistance value of the resistor RT, R1 is the resistance value of the resistor R1, and VRef is the output voltage of the voltage reference source.

[0024] Furthermore, a voltage reference source temperature drift correction method comprises the following steps:

[0025] (1) Connecting the first pin and the second pin of the voltage reference source, and adding a bias voltage to the two connected pins through a voltage divider resistor;

[0026] (2) Two series resistors are connected to two connected pins, and the connection node between the two series resistors is used as a voltage output node;

[0027] (3) configuring the grounding resistor in step (2) as a thermistor with a negative temperature coefficient;

[0028] (4) Adjust the bias voltage so that the bias voltage is greater than the voltage of the connection node between the two connected pins of the voltage reference source, so that the voltage reference source is turned on.

[0029] The beneficial effects of the present application are as follows: the present invention adopts a resistor voltage division method, cleverly utilizing the temperature characteristics of a voltage reference source and a thermistor to correct the reference voltage, thereby reducing the variation of the reference voltage with temperature. It has the characteristics of simple design and easy adjustment, and is very suitable for use in module power supplies with a small size and dense components. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a circuit schematic diagram of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] Please refer to Figure 1The present application proposes a voltage reference source temperature drift correction module and method, which uses fewer components to improve the high and low temperature deviation phenomenon of the voltage reference source, effectively reduces the temperature coefficient of the module power supply, solves the problem of low or high output voltage and failure of output overvoltage protection caused by the deviation of the voltage reference source U1 under high and low temperature conditions, and improves the reliability of the module power supply product. In this embodiment, the correction module includes a power supply unit, a voltage reference source U1, and a temperature-controlled voltage divider unit. The power supply unit is connected to the voltage reference source and is configured to provide a bias voltage to the voltage reference source U1. The voltage reference source U1 includes three pins, one of which is grounded, and the other two pins are connected, and the connection node of the two connected pins is connected to the power supply unit. One end of the voltage divider unit is connected to the connection node of the two connected pins, and the other end of the voltage divider unit is grounded. The power supply unit provides a bias voltage to the voltage reference source U1, so that the voltage reference source U1 is turned on and outputs a corresponding voltage. The output voltage of the voltage reference source U1 is divided by the voltage divider unit to obtain a reference voltage. When the temperature changes, the output voltage of the voltage reference source U1 changes. Through the temperature characteristics of the voltage divider unit, the voltage divider unit reduces the change of the reference voltage with temperature, stabilizes the output voltage, and improves the reliability of the module power supply product.

[0035] Please refer to Figure 1 , further, in order to better provide a stable and appropriate bias voltage. In this embodiment, the power supply unit includes a voltage-dividing resistor R2, one end of the voltage-dividing resistor R2 is connected to the voltage-stabilizing power supply VCC, and the other end of the voltage-dividing resistor R2 is connected to the connection node of the two connected pins of the voltage reference source U1. The voltage provided by the voltage-stabilizing power supply VCC reaches the connection node of the connected pins of the voltage reference source U1 after being divided by the voltage-dividing resistor R2. When the voltage provided by the voltage-stabilizing power supply VCC is greater than the voltage of the connection node, the voltage reference source U1 is turned on, otherwise, the voltage reference source U1 is not turned on. The voltage-dividing resistor R2 can be used to adjust a stable and appropriate input current, so that the voltage reference source U1 is turned on and the voltage reference source U1 is protected.

[0036] Please refer to Figure 1 , further, in order to facilitate the coordination with the voltage reference source U1 and control the conduction of the voltage reference source U1. In this embodiment, the three pins of the voltage reference source U1 are pin 1, pin 2 and pin 3, respectively. Pin 1 is configured as an anode, pin 2 is configured as a voltage output port, and pin 3 is configured as a cathode. Pin 1 and pin 2 are connected, and pin 3 is grounded. By connecting pin 1 and pin 2, as long as the voltage of the voltage-stabilized power supply VCC is greater than the node voltage of the two connected pins, the voltage reference source U1 can be turned on. After the voltage reference source U1 is turned on, the node voltage is stabilized within a certain voltage range and will only be affected by temperature. Among them, the model of the voltage reference source U1 can be TL431.

[0037] Please refer to Figure 1 , further, in order to correct the reference voltage VREF, the change of the reference voltage VREF with temperature is reduced. In this embodiment, the voltage divider unit includes a resistor R1 and a resistor RT, the resistor R1 and the resistor RT are connected in series, the end of the resistor R1 away from the resistor RT is connected to the connection node of the two connected pins of the voltage reference source, the end of the resistor RT away from the resistor R1 is grounded, the resistor RT is configured as a thermistor, and the resistor RT is a negative temperature coefficient resistor (the resistance of the resistor RT will decrease with the increase of temperature), and the node connected by the resistor R1 and the resistor RT is the reference voltage VREF output node. When the temperature rises, the output voltage VRef of the voltage reference source U1 increases, resulting in a positive shift of the reference voltage VREF. Since the resistor RT is a negative temperature coefficient resistor, its resistance decreases with the increase of temperature. Therefore, when the temperature rises, the resistance of the resistor RT decreases, and its voltage division decreases, so that VREF is negatively offset, reducing the positive offset of VREF caused by the voltage reference source due to the increase of temperature. When the temperature decreases, the output voltage VRef of the voltage reference source U1 decreases, causing VREF to shift negatively. Since the resistor RT is a negative temperature coefficient resistor, its resistance increases as the temperature decreases, and its voltage division increases, causing VREF to shift positively, reducing the negative offset of VREF caused by the temperature lowering the voltage reference source.

[0038] The connection node where the resistor R1 is connected to the resistor RT is the output node, and the calculation formula for the output voltage of the output node is:

[0039]

[0040] Among them, VREF is the output voltage of the output node, RT is the resistance value of the resistor RT, R1 is the resistance value of the resistor R1, and VRef is the output voltage of the voltage reference source.

[0041] Please refer to Figure 1 , further, in order to provide a clearer working process. In this embodiment, a voltage reference source temperature drift correction method is also disclosed, which first connects the first pin and the second pin of the voltage reference source that are different from the ground pin, and incorporates a bias voltage into the two connected pins through a voltage divider resistor; then incorporates two series resistors into the two connected pins, and the connection node between the two series resistors is used as a voltage output node; then configures the ground resistor as a thermistor with a negative temperature coefficient; finally, adjusts the bias voltage so that the bias voltage is greater than the voltage of the connection node of the two connected pins of the voltage reference source, so that the voltage reference source is turned on.

[0042] The working principle of the present invention is as follows: when the voltage-stabilized power supply VCC is greater than the output voltage VRef of the voltage reference source U1, the voltage reference source U1 is turned on, and the output voltage of the second pin of the voltage reference source U1 is VRef. The output voltage VRef of the voltage reference source U1 is divided by the resistor R1 and the resistor RT to generate the reference voltage VREF. When the temperature rises, the output voltage VRef of the voltage reference source U1 rises, resulting in a positive shift of the reference voltage VREF, but the resistance value of the resistor RT decreases, the voltage division decreases, and the reference voltage VREF is negatively shifted. Through the above adjustment, the positive shift of the reference voltage VREF caused by the voltage reference source due to the temperature increase is reduced. Similarly, when the temperature decreases, the output voltage VRef of the voltage reference source U1 decreases, resulting in a negative shift of the reference voltage VREF, but the resistance value of the resistor RT increases, the voltage division increases, and the reference voltage VREF is positively shifted. Through the above adjustment, the negative shift of the reference voltage VREF caused by the voltage reference source due to the temperature decrease is reduced.

[0043] Of course, the present application may have many other implementations. Based on the present implementation, other implementations obtained by ordinary technicians in this field without any creative work are all within the scope of protection of the present application.

Claims

1. A voltage reference source temperature drift correction module, characterized in that: include: Power supply unit; Voltage reference source; Temperature controlled pressure dividing unit; The power supply unit is connected to a voltage reference source and is configured to provide a bias voltage to the voltage reference source; The voltage reference source includes three pins, one of which is grounded, the other two pins are connected, and the connection node of the two connected pins is connected to the power supply unit; One end of the voltage dividing unit is connected to a connection node of two connected pins, and the other end of the voltage dividing unit is grounded.

2. The voltage reference source temperature drift correction module according to claim 1, characterized in that: The power supply unit comprises a voltage-dividing resistor R2, one end of the voltage-dividing resistor R2 is connected to a voltage-stabilizing power supply, and the other end of the voltage-dividing resistor R2 is connected to a connection node of two connected pins of a voltage reference source.

3. The voltage reference source temperature drift correction module according to claim 1, characterized in that: The three pins of the voltage reference source are respectively pin 1, pin 2 and pin 3, the pin 1 is configured as an anode, the pin 2 is configured as a voltage output port, and the pin 3 is configured as a cathode.

4. The voltage reference source temperature drift correction module according to claim 1, characterized in that: The voltage dividing unit includes a resistor R1 and a resistor RT, the resistor R1 and the resistor RT are connected in series, one end of the resistor R1 away from the resistor RT is connected to a connection node of two connected pins of a voltage reference source, one end of the resistor RT away from the resistor R1 is grounded, and the resistor RT is configured as a thermistor.

5. The voltage reference source temperature drift correction module according to claim 4, characterized in that: The resistor RT is a negative temperature coefficient resistor.

6. The voltage reference source temperature drift correction module according to claim 5, characterized in that: The connection node where the resistor R1 is connected to the resistor RT is an output node, and the calculation formula of the output voltage of the output node is: Among them, VREF is the output voltage of the output node, RT is the resistance value of the resistor RT, R1 is the resistance value of the resistor R1, and VRef is the output voltage of the voltage reference source.

7. A method for correcting temperature drift of a voltage reference source, characterized in that: The following steps are involved: (1) Connecting the first pin and the second pin of the voltage reference source, and adding a bias voltage to the two connected pins through a voltage divider resistor; (2) Two series resistors are connected to two connected pins, and the connection node between the two series resistors is used as a voltage output node; (3) configuring the grounding resistor in step (2) as a thermistor with a negative temperature coefficient; (4) Adjust the bias voltage so that the bias voltage is greater than the voltage of the connection node between the two connected pins of the voltage reference source, so that the voltage reference source is turned on.

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