A circuit and adjustment method for setting output voltage by adjusting reference voltage

Abstract

The present invention discloses a circuit and a regulating method for setting an output voltage by adjusting a reference voltage, comprising an output voltage remote compensation unit, an output voltage loop compensation unit and an output voltage unit, and also comprising an operational amplifier N1; the output voltage remote compensation unit, the output voltage loop compensation unit, the operational amplifier N1 and the output voltage unit are connected in sequence; the output voltage unit comprises an output voltage upward adjustment unit and an output voltage downward adjustment unit; the output voltage upward adjustment unit and the output voltage downward adjustment unit are connected in parallel; the output end of the operational amplifier N1 outputs a voltage to the output voltage remote compensation unit via the voltage upward adjustment unit or the output voltage downward adjustment unit. The present invention arranges an operational amplifier, and reasonably calculates the resistance by utilizing the virtual short and virtual open functions of the operational amplifier, so as to achieve an output voltage upward adjustment of N% or an output voltage downward adjustment of N%. Through the above arrangement, the entire circuit principle structure is simple, the power consumption is small, and the reliability is high.

Description

Technical Field

[0001] The invention belongs to the technical field of power supply, and relates to voltage regulation technology, in particular to a circuit and a regulation method for setting an output voltage by regulating a reference voltage. Background Art

[0002] Switching power supplies are DC / DC converters used as secondary power supplies for systems and are widely used in military and civilian electronic systems such as aerospace, aviation, shipping, weapons, electronics, railways, communications, medical electronics, and industrial automation equipment. In the design of switching power supplies, adjustable output voltage has been used as a functional assessment indicator. Usually, the output voltage is adjusted by changing the upper and lower resistance values ​​related to the output voltage. However, the upper and lower resistance values ​​of some power supplies are fixed in the circuit and cannot be modified. Therefore, this traditional output voltage adjustment method can no longer meet the design requirements of the power module. Summary of the invention

[0003] The purpose of the present invention is to provide a circuit and a method for setting an output voltage by adjusting a reference voltage, so as to solve the problem that the upper and lower resistance values ​​of a power supply are fixed in the circuit and cannot be modified, resulting in an unadjustable output voltage.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A circuit for setting an output voltage by adjusting a reference voltage, comprising an output voltage remote compensation unit, an output voltage loop compensation unit and an output voltage unit, and also comprising an operational amplifier N1;

[0006] The output voltage remote compensation unit, the output voltage loop compensation unit, the operational amplifier N1 and the output voltage unit are connected in sequence;

[0007] The output voltage unit includes an output voltage upward adjustment unit and an output voltage downward adjustment unit; the output voltage upward adjustment unit and the output voltage downward adjustment unit are connected in parallel;

[0008] The output end of the operational amplifier N1 outputs the voltage through a voltage up-regulation unit or an output voltage down-regulation unit, and then to an output voltage remote compensation unit.

[0009] Further, the output voltage increasing unit includes a resistor R4, a resistor R5 and an increasing terminal;

[0010] One end of the resistor R4 is connected to one end of the resistor R5, the other end of the resistor R4 is connected to the output end of the operational amplifier N1, one end of the resistor R5 is connected to one end of the capacitor C2 in the output voltage loop compensation unit, and the other end of the resistor R5 is connected to the up-regulation end.

[0011] Further, the output voltage down-regulation unit includes a resistor R6, a resistor R7 and a down-regulation terminal;

[0012] One end of the resistor R6 is connected to one end of the resistor R7, the other end of the resistor R6 is connected to the output end of the operational amplifier, one end of the resistor R7 is connected to the negative input end of the operational amplifier, and the other end of the resistor R7 is connected to the down-regulation end.

[0013] Further, the output voltage loop compensation unit includes a resistor R2, a capacitor C2 and a capacitor C3;

[0014] One end of the resistor R2 and the capacitor C3 is connected to the capacitor C1 and one end of the resistor R1 of the output voltage remote compensation unit (1), the other end of the resistor R2 is connected to one end of the capacitor C2, and the other end of the capacitor C3 is connected to the other end of the capacitor C2.

[0015] Further, the output voltage remote compensation unit includes a capacitor C1 and a resistor R1;

[0016] One end of the capacitor C1 and the resistor R1 is connected to the output voltage, and the other end of the capacitor C1 and the resistor R1 is connected to one end of the resistor R2 and the capacitor C3.

[0017] Furthermore, it also includes a filtering circuit, which includes a resistor R3 and a capacitor C4, one end of the resistor R3 is connected to the output end of the output voltage remote compensation unit, one end of the capacitor C4 is grounded, and the other ends of the resistor R3 and the capacitor C4 are connected to the positive input end of the operational amplifier N1.

[0018] On the other hand, the present invention also discloses a method for adjusting an output voltage, based on the above-mentioned circuit for setting an output voltage by adjusting a reference voltage, comprising the following steps:

[0019] The calculation steps to achieve an N% increase in output voltage are as follows:

[0020] The increasing terminal of the output voltage increasing unit is grounded, and point V1 is equivalent to the reference voltage. To achieve N% increase, the output voltage of the operational amplifier N1 is equivalent to (100-N)% of the reference voltage. Then the ratio of V1 to R5 is equal to the ratio of the voltage at point V1 minus the output voltage of the operational amplifier N1 to R4, that is, R4=R5×N%.

[0021] Furthermore, the method further comprises the following steps:

[0022] The calculation steps to achieve output voltage reduction by N% are as follows:

[0023] The down-regulation end of the output voltage down-regulation unit is grounded, and the positive input and negative input of the operational amplifier N1 can be equivalent to the reference voltage. In order to achieve N% down-regulation, the output end of the operational amplifier N1 needs to be equivalent to (100+N)% of the reference voltage. Then, the ratio of the output voltage of the operational amplifier N1 minus the input negative voltage to R6 is equal to the ratio of the input negative voltage to R7, that is, R6=R7×N%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The circuit of the present invention for setting the output voltage by adjusting the reference voltage, through the output voltage remote compensation unit, compensates for the low output voltage caused by excessive output current and long power supply distance, and then adjusts the response speed and stability of the output voltage through the output voltage loop compensation unit. The output voltage after remote compensation and loop compensation enters the output voltage up-regulation unit and the output voltage down-regulation unit, wherein the up-regulation end is grounded, the reference voltage is pulled down by N%, and the resistance is reasonably calculated through the virtual short and virtual open functions of the operational amplifier to achieve the output voltage up-regulation by N%; the down-regulation end is grounded, the reference voltage is raised by N%, and the resistance is reasonably calculated through the virtual short and virtual open functions of the operational amplifier to achieve the output voltage down-regulation by N%. The whole circuit principle and structure are simple, the power consumption is low, the reliability is high, the space occupied is small, and the circuit applicability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a system block diagram of the present invention;

[0028] Figure 2 It is a block diagram of the circuit principle diagram of the present invention.

[0029] In the figure: 1. Output voltage remote compensation unit; 2. Output voltage loop compensation unit; 3. Output voltage up-regulation unit; 4. Output voltage down-regulation unit. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Therefore, the detailed description of the embodiments of the present invention provided in the following figures is not intended to limit the scope of the claimed invention but is merely representative of selected embodiments of the present invention.

[0032] Traditionally, in the design of switching power supplies, adjustable output voltage has been used as a functional assessment indicator. Usually, the output voltage is adjusted by changing the upper and lower resistance values ​​related to the output voltage. However, the upper and lower resistance values ​​of some power supplies are fixed in the circuit and cannot be modified. Therefore, this traditional output voltage adjustment method can no longer meet the design requirements of the power module.

[0033] In view of the above technical problems, the present application proposes a circuit for setting an output voltage by adjusting a reference voltage, comprising an output voltage remote compensation unit 1, an output voltage loop compensation unit 2 and an output voltage unit, and also comprising an operational amplifier N1;

[0034] The output voltage remote compensation unit 1, the output voltage loop compensation unit 2, the operational amplifier N1 and the output voltage unit are connected in sequence;

[0035] The output voltage unit includes an output voltage upward adjustment unit 3 and an output voltage downward adjustment unit 4; the output voltage upward adjustment unit 3 and the output voltage downward adjustment unit 4 are connected in parallel;

[0036] The output end of the operational amplifier N1 outputs voltage to the output voltage remote compensation unit 1 via the voltage up-regulation unit 3 or the output voltage down-regulation unit 4 .

[0037] The output voltage remote compensation unit 1 is used to compensate for the low output voltage caused by excessive output current and long power supply distance.

[0038] An output voltage loop compensation unit 2, used for adjusting the response speed and stability of the output voltage through loop compensation;

[0039] The output voltage increasing unit 3 grounds the increasing terminal, pulls down the reference voltage by N%, and reasonably calculates the resistance through the virtual short and virtual open functions of the operational amplifier N1, so as to increase the output voltage by N%.

[0040] The output voltage down-regulation unit 4 grounds the down-regulation terminal, increases the reference voltage by N%, and reasonably calculates the resistance through the virtual short and virtual open functions of the operational amplifier N1, thereby achieving the output voltage down-regulation by N%.

[0041] Specifically, the input end of the output voltage remote compensation unit 1 is connected to the output voltage, and the output end is connected to the input end of the output voltage loop compensation unit 2, which is used to compensate for the low output voltage caused by excessive output current and long power supply distance;

[0042] The input end of the output voltage loop compensation unit 2 is connected to the output end of the output voltage remote compensation unit 1, and the output end of the output voltage loop compensation unit 2 is connected to the output voltage up-regulation unit 3 and the output voltage down-regulation unit 4, so as to adjust the response speed and stability of the output voltage through loop compensation;

[0043] The input end of the output voltage increasing unit 3 is connected to the output end of the output voltage loop compensation unit 2, the increasing end is grounded, the reference voltage is pulled down by N%, and the resistance is reasonably calculated through the virtual short and virtual open functions of the operational amplifier to achieve the output voltage increasing by N%;

[0044] The input end of the output voltage reduction unit 4 is connected to the output end of the output voltage loop compensation unit 2, the reduction end is grounded, the reference voltage is increased by N%, and the resistance is reasonably calculated through the virtual short and virtual open functions of the operational amplifier to achieve the output voltage reduction of N%.

[0045] Based on the above description, the embodiment of the present invention proposes a method as follows Figure 1-2 A circuit for setting an output voltage by adjusting a reference voltage is shown. The output voltage remote compensation unit 1 of this embodiment includes a capacitor C1 and a resistor R1. One end of the capacitor C1 and the resistor R1 in the output voltage remote compensation unit is connected to the output voltage, and the other end of the capacitor C1 and the resistor R1 is connected to one end of the resistor R2 and the capacitor C3.

[0046] The output voltage loop compensation unit 2 includes a resistor R2, a capacitor C2, and a capacitor C3. One end of the resistor R2 and the capacitor C3 in the output voltage loop compensation unit 2 is connected to one end of the capacitor C1 and the resistor R1 of the output voltage remote compensation unit, the other end of the resistor R2 is connected to one end of the capacitor C2, and the other end of the capacitor C3 is connected to the other end of the capacitor C2.

[0047] The output voltage increasing unit 3 includes a resistor R4, a resistor R5, and an operational amplifier N1. One end of the resistor R4 in the output voltage increasing unit 3 is connected to one end of the resistor R5, and the other end of the resistor R4 is connected to the output end of the operational amplifier. One end of the resistor R5 is connected to one end of C2 in the output voltage loop compensation unit, and the other end of the resistor R5 is connected to the output voltage increasing end.

[0048] The output voltage reduction unit 4 includes a resistor R6, a resistor R7, and an operational amplifier N1. One end of the resistor R6 in the output voltage reduction unit 4 is connected to one end of the resistor R7, the other end of the resistor R6 is connected to the output end of the operational amplifier, one end of the resistor R7 is connected to the negative input end of the operational amplifier, and the other end of the resistor R7 is connected to the output voltage reduction end.

[0049] One end of the resistor R3 is connected to the output end of the output voltage remote compensation unit 1 , one end of the capacitor C4 is grounded, and the other ends of the resistor R3 and the capacitor C4 are connected to the positive input end of the operational amplifier N1 .

[0050] The calculation steps of the output voltage increasing unit 3 to increase the output voltage by N% are as follows:

[0051] The upward adjustment end is grounded, and point V1 is equivalent to the reference voltage. To achieve N% upward adjustment, the output voltage of operational amplifier N1 is equivalent to (100-N)% of the reference voltage. Then the ratio of V1 to R5 is equal to the ratio of the voltage at point V1 minus the output voltage of operational amplifier N1 to R4, that is, R4=R5×N%.

[0052] The calculation steps of the output voltage down-regulation unit 4 to achieve down-regulation of the output voltage by N% are as follows:

[0053] The down-regulation terminal is grounded, and the positive input and negative input of the operational amplifier N1 can be equivalent to the reference voltage. To achieve N% down-regulation, the output terminal of the operational amplifier N1 needs to be equivalent to (100+N)% of the reference voltage. Then, the ratio of the output terminal voltage of the operational amplifier N1 minus the input negative terminal voltage to R6 is equal to the ratio of the input negative terminal voltage to R7, that is, R6=R7×N%;

[0054] Through the above calculation, there is no need to clarify the actual value of the voltage at each point. It is only necessary to know the proportional relationship between the voltage at each point and the reference voltage through logical analysis, and the voltage up and down adjustment function can be achieved by configuring the resistance value of the corresponding resistor.

[0055] The working principle of this embodiment is as follows:

[0056] In the output voltage remote compensation unit 1 , the output voltage is compensated for the low output voltage caused by excessive output current and long power supply distance through the capacitor C1 and the resistor R1 , and becomes the DC voltage supplied to the output voltage loop compensation unit 2 .

[0057] The output voltage loop compensation unit 2 adjusts the response speed and stability of the output voltage through the resistor R2, the capacitor C2, and the capacitor C3, and forms a stable voltage signal to enter the output voltage up-regulation unit 3 and the output voltage down-regulation unit 4.

[0058] In the output voltage increasing unit 3, the increasing terminal is grounded, the reference voltage is pulled down by N%, and the resistors R4 and R5 are reasonably calculated by the virtual short and virtual open functions of the operational amplifier to achieve the output voltage increasing by N%.

[0059] In the output voltage down-regulation unit 4, the down-regulation end is grounded, and the reference voltage is increased by N%. The resistors R6 and R7 are reasonably calculated by the virtual short and virtual open functions of the operational amplifier to achieve the output voltage down-regulation by N%.

[0060] As can be seen from the above, a circuit for setting the output voltage by adjusting the reference voltage in this embodiment is suitable for various types of switching power supplies. The output voltage increase and output voltage decrease functions can be realized through this circuit. The circuit requires a small number of components, has low power consumption, and is safe and reliable. It is beneficial to reduce the size of the power module, improve the reliability of the converter, and provide a guarantee for system safety.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0063] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific circumstances; the preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and use the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A circuit for setting an output voltage by adjusting a reference voltage, comprising an output voltage remote compensation unit (1), an output voltage loop compensation unit (2) and an output voltage unit, It is characterized in that Also included is an operational amplifier N1; The output voltage remote compensation unit (1), the output voltage loop compensation unit (2), the operational amplifier N1 and the output voltage unit are connected in sequence; The output voltage unit comprises an output voltage upward adjustment unit (3) and an output voltage downward adjustment unit (4); the output voltage upward adjustment unit (3) and the output voltage downward adjustment unit (4) are connected in parallel; The output end of the operational amplifier N1 outputs a voltage through an output voltage up-regulation unit (3) or an output voltage down-regulation unit (4) and then to an output voltage remote compensation unit (1).

2. A circuit for setting an output voltage by adjusting a reference voltage according to claim 1, It is characterized in that The output voltage increasing unit (3) comprises a resistor R4, a resistor R5 and an increasing terminal; One end of the resistor R4 is connected to one end of the resistor R5, the other end of the resistor R4 is connected to the output end of the operational amplifier N1, one end of the resistor R5 is connected to one end of the capacitor C2 in the output voltage loop compensation unit (2), and the other end of the resistor R5 is connected to the up-regulation end.

3. A circuit for setting an output voltage by adjusting a reference voltage according to claim 2, It is characterized in that The output voltage down-regulation unit (4) comprises a resistor R6, a resistor R7 and a down-regulation terminal; One end of the resistor R6 is connected to one end of the resistor R7, the other end of the resistor R6 is connected to the output end of the operational amplifier, one end of the resistor R7 is connected to the negative input end of the operational amplifier, and the other end of the resistor R7 is connected to the down-regulation end.

4. A circuit for setting an output voltage by adjusting a reference voltage according to claim 3, It is characterized in that The output voltage loop compensation unit (2) comprises a resistor R2, a capacitor C2 and a capacitor C3; One end of the resistor R2 and the capacitor C3 is connected to the capacitor C1 and one end of the resistor R1 of the output voltage remote compensation unit (1), the other end of the resistor R2 is connected to one end of the capacitor C2, and the other end of the capacitor C3 is connected to the other end of the capacitor C2.

5. A circuit for setting an output voltage by adjusting a reference voltage according to claim 4, It is characterized in that The output voltage remote compensation unit (1) comprises a capacitor C1 and a resistor R1; One end of the capacitor C1 and the resistor R1 is connected to the output voltage, and the other end of the capacitor C1 and the resistor R1 is connected to one end of the resistor R2 and the capacitor C3.

6. A circuit for setting an output voltage by adjusting a reference voltage according to claim 5, It is characterized in that The invention also comprises a filter circuit, which comprises a resistor R3 and a capacitor C4, one end of the resistor R3 is connected to the output end of the output voltage remote compensation unit (1), one end of the capacitor C4 is grounded, and the other ends of the resistor R3 and the capacitor C4 are connected to the positive input end of the operational amplifier N1.

7. A method for adjusting an output voltage, based on the circuit for setting an output voltage by adjusting a reference voltage according to any one of claims 1 to 6, It is characterized in that The following steps are involved: The calculation steps to achieve an N% increase in output voltage are as follows: The increasing terminal of the output voltage increasing unit (3) is grounded, and point V1 is equivalent to the reference voltage. To achieve N% increase, the voltage at the output terminal of the operational amplifier N1 is equivalent to (100-N)% of the reference voltage. Then, the ratio of V1 to the resistor R5 is equal to the ratio of the voltage at point V1 minus the voltage at the output terminal of the operational amplifier N1 to the resistor R4, that is, R4=R5×N%.

8. The method for adjusting output voltage according to claim 7, It is characterized in that The following steps are also included: The calculation steps to achieve output voltage reduction by N% are as follows: The down-regulation end of the output voltage down-regulation unit (4) is grounded, and the positive input and negative input of the operational amplifier N1 can be equivalent to the reference voltage. In order to achieve N% down-regulation, the output end of the operational amplifier N1 needs to be equivalent to (100+N)% of the reference voltage. Then, the ratio of the output end voltage of the operational amplifier N1 minus the input negative end voltage to the resistor R6 is equal to the ratio of the input negative end voltage to the resistor R7, that is, R6=R7×N%.

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