Voltage generating circuit and bandgap reference device

Abstract

The application provides a voltage generating circuit and a band gap reference device, and belongs to the technical field of power electronics. The voltage generating circuit comprises a current generating unit, a first power supply output unit and a second power supply output unit; the output ends of the current generating unit are connected with the first power supply output unit and the second power supply output unit respectively, and the current generating unit is used for generating a current source; the first power supply output unit is used for generating a first power supply voltage according to the current source; the second power supply output unit comprises a first switch tube, and is used for generating a second power supply voltage according to the current source and controlling the size of the second power supply voltage based on a clock signal through the first switch tube, and the second power supply voltage is a variable voltage. The application can improve the stability of the output voltage.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a voltage generation circuit and a bandgap reference device. Background Technology

[0002] In the field of power electronics, since most process parameters change with temperature, if the process parameters of a voltage generation circuit are unstable, the output voltage value will be unstable. Therefore, a voltage generation circuit that can maintain a constant generated voltage in response to temperature changes is needed.

[0003] In the prior art, for voltage generation circuits, in order to keep the generated voltage constant with temperature changes, it is usually necessary to generate voltage based on the voltage difference between two transistors. The calculation of the differential voltage involves coefficients that exhibit both positive and negative temperature coefficients. Based on the changes in these coefficients, a voltage quantity that does not change with temperature can be generated.

[0004] However, due to differences in manufacturing processes, even transistors and triodes of the same specifications can have errors. This can lead to inaccurate temperature coefficients of the generated voltage differences, resulting in unstable temperature coefficients of the final output voltage. Summary of the Invention

[0005] The purpose of this application is to provide a voltage generation circuit and a bandgap reference device that can improve the stability of the output voltage.

[0006] The embodiments of this application are implemented as follows:

[0007] One aspect of this application provides a voltage generating circuit, including: a current generating unit, a first power supply output unit, and a second power supply output unit;

[0008] The output terminal of the current generating unit is connected to the first power supply output unit and the second power supply output unit respectively. The current generating unit is used to generate a current source.

[0009] The first power supply output unit is used to generate a first power supply voltage according to the current source;

[0010] The second power supply output unit includes a first switching transistor. The second power supply output unit is used to generate a second power supply voltage according to the current source, and to control the magnitude of the second power supply voltage based on a clock signal through the first switching transistor. The second power supply voltage is a variable voltage.

[0011] Optionally, the current generating unit includes: a second switching transistor and a third switching transistor;

[0012] The control terminals of the second and third switches are connected to the control voltage. The first terminal of the second switch is connected to the first terminal of the third switch and connected to the power supply voltage. The second terminal of the second switch is connected to the first power supply output unit, and the second terminal of the third switch is connected to the second power supply output unit.

[0013] Optionally, the first power supply output unit includes: a first transistor, the first terminal of the first transistor being connected to the second terminal of the second switch and outputting a first power supply voltage, and the second and third terminals of the first transistor being grounded.

[0014] Optionally, the second power supply output unit further includes: a second transistor and a third transistor;

[0015] The first terminal of the first switch is connected to the second terminal of the third switch and the first terminal of the third transistor respectively, and outputs the second power supply voltage. The second terminal of the first switch is connected to the first terminal of the second transistor. The control terminal of the first switch is connected to the clock signal.

[0016] The second and third terminals of the second transistor are grounded;

[0017] The second and third terminals of the third transistor are grounded.

[0018] Optionally, the first switching transistor is an N-type metal-oxide-semiconductor field-effect transistor.

[0019] Optionally, both the second and third switching transistors are P-type metal-oxide-semiconductor field-effect transistors.

[0020] Optionally, the first transistor is a bipolar junction transistor (BJT).

[0021] Optionally, both the second and third transistors are bipolar transistors.

[0022] Optionally, the first switch is turned on when the clock signal is high, and turned off when the clock signal is low.

[0023] In another aspect of this application, a bandgap reference device is provided, including a voltage generation circuit and a discrete voltage summing circuit. The voltage generation circuit is connected to the discrete voltage summing circuit. The voltage generation circuit is used to output a first supply voltage and a second supply voltage to the discrete voltage summing circuit. The discrete voltage summing circuit is used to generate a bandgap reference voltage based on the first supply voltage and the second supply voltage.

[0024] The beneficial effects of the embodiments of this application include:

[0025] The voltage generation circuit and bandgap reference device provided in this application embodiment may include a current generation unit, a first power supply output unit, and a second power supply output unit. The output terminal of the current generation unit is connected to both the first and second power supply output units, and the current generation unit is used to generate a current source. The first power supply output unit is used to generate a first power supply voltage based on the current source. The second power supply output unit includes a first switching transistor, and is used to generate a second power supply voltage based on the current source. The first switching transistor controls the magnitude of the second power supply voltage based on a clock signal, and the second power supply voltage is a variable voltage. By having the same current generation unit provide power to both the first and second power supply output units, the magnitude of the current source can be kept the same, thereby improving the avoidance of current errors in the circuit. Furthermore, in the second power supply output unit, the switching on and off of the first switching transistor is controlled based on a clock signal, thereby changing the magnitude of the second power supply voltage. The voltage difference generated by the switching on and off of the first switching transistor achieves the output of a second power supply voltage that meets actual requirements, thus improving the stability of the output voltage. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the voltage generation circuit provided in an embodiment of this application;

[0028] Figure 2 This is a schematic diagram of the current generating unit in the voltage generating circuit provided in the embodiments of this application;

[0029] Figure 3 This is a schematic diagram of the structure of the first power supply output unit in the voltage generation circuit provided in the embodiments of this application;

[0030] Figure 4 This is a schematic diagram of the structure of the second power supply output unit in the voltage generation circuit provided in the embodiments of this application;

[0031] Figure 5 This is a schematic diagram illustrating the relationship between the second power supply voltage and the clock signal provided in an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the overall structure of the voltage generation circuit provided in the embodiments of this application;

[0033] Figure 7This is a schematic diagram of the bandgap reference device provided in an embodiment of this application.

[0034] Icons: 10 - Voltage generation circuit; 20 - Discrete voltage summation circuit; 100 - Current generation unit; 200 - First power supply output unit; 300 - Second power supply output unit; M1 - First switching transistor; M2 - Second switching transistor; M3 - Third switching transistor; Q1 - First transistor; Q2 - Second transistor; Q3 - Third transistor. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this application, it should be noted that the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] The specific structure and connection relationship of the voltage generation circuit provided in the embodiments of this application will be explained in detail below.

[0040] Figure 1 Please refer to the schematic diagram of the voltage generation circuit provided in the embodiment of this application. Figure 1 The voltage generation circuit includes: a current generation unit 100, a first power supply output unit 200, and a second power supply output unit 300.

[0041] The output terminal of the current generating unit 100 is connected to the first power supply output unit 200 and the second power supply output unit 300 respectively. The current generating unit 100 is used to generate a current source. The first power supply output unit 200 is used to generate a first power supply voltage according to the current source. The second power supply output unit 300 includes a first switching transistor M1. The second power supply output unit 300 is used to generate a second power supply voltage according to the current source, and controls the magnitude of the second power supply voltage based on a clock signal through the first switching transistor M1. The second power supply voltage is a variable voltage.

[0042] Optionally, the current generating unit 100 can specifically generate two current sources of the same size and output them to the first power supply output unit 200 and the second power supply output unit 300 respectively.

[0043] The first power supply output unit 200 can generate a first power supply voltage. It should be noted that the first power supply voltage can be a constant voltage.

[0044] The second power supply output unit 300 can generate a second power supply voltage. It should be noted that the second power supply voltage can be a variable voltage, and the high and low levels of the second power supply voltage can be switched by adjusting the on / off state of the first switching transistor M1. The first switching transistor M1 can be controlled by a clock signal. When the clock signal is high, the first switching transistor M1 is turned on, and the second power supply voltage is a low potential voltage; when the clock signal is low, the first switching transistor M1 is turned off, and the second power supply voltage is a high potential voltage.

[0045] It should be noted that the first switching transistor can be an N-type metal-oxide-semiconductor field-effect transistor.

[0046] This application provides a voltage generation circuit that includes a current generation unit, a first power supply output unit, and a second power supply output unit. The output terminal of the current generation unit is connected to both the first and second power supply output units, and the current generation unit generates a current source. The first power supply output unit generates a first power supply voltage based on the current source. The second power supply output unit includes a first switching transistor and generates a second power supply voltage based on the current source. The first switching transistor controls the magnitude of the second power supply voltage based on a clock signal, and the second power supply voltage is a variable voltage. By having the same current generation unit supply power to both the first and second power supply output units, the magnitude of the current source can be kept the same, thereby improving the avoidance of current errors in the circuit. Furthermore, in the second power supply output unit, the switching on and off of the first switching transistor is controlled based on a clock signal, thereby changing the magnitude of the second power supply voltage. The voltage difference generated by the switching on and off of the first switching transistor achieves the output of a second power supply voltage that meets actual requirements, improving the stability of the output voltage.

[0047] The specific structural relationship of the current generating unit in the voltage generating circuit provided in the embodiments of this application will be explained in detail below.

[0048] Figure 2 Please refer to the schematic diagram of the current generating unit in the voltage generating circuit provided in the embodiments of this application. Figure 2 The current generating unit 100 includes a second switching transistor M2 and a third switching transistor M3.

[0049] Among them, the control terminals of the second switch M2 and the third switch M3 are connected to the control voltage, the first terminal of the second switch M2 is connected to the first terminal of the third switch M3 and connected to the power supply voltage, the second terminal of the second switch M2 is connected to the first power supply output unit 200, and the second terminal of the third switch M3 is connected to the second power supply output unit 300.

[0050] Optionally, the control terminals of the second switch M2 and the third switch M3 can be connected to the same control voltage. The first terminal of the second switch M2 and the first terminal of the third switch M3 are connected to the same power supply voltage VDD. When the control voltage is high, the second switch M2 and the third switch M3 are turned on simultaneously, thereby enabling the power supply voltage to power the entire voltage generation circuit.

[0051] It should be noted that the second switch M2 and the third switch M3 can be two switch transistors with exactly the same parameters, specifically, they can be P-type metal-oxide-semiconductor field-effect transistors.

[0052] The circuit described above can generate two current sources of the same size, which can be input to the first power supply output unit 200 and the second power supply output unit 300, respectively.

[0053] The specific structural relationship of the first power supply output unit in the voltage generation circuit provided in the embodiments of this application will be explained in detail below.

[0054] Figure 3 Please refer to the schematic diagram of the first power supply output unit in the voltage generation circuit provided in the embodiments of this application. Figure 3 The first power supply output unit 200 includes: a first transistor Q1, the first terminal of the first transistor Q1 is connected to the second terminal of the second switch M2 and outputs a first power supply voltage, and the second and third terminals of the first transistor Q1 are both grounded.

[0055] It should be noted that the first transistor Q1 can be a bipolar transistor.

[0056] For the first power supply output unit 200, after the current source generated by the current generation unit 100 flows into the first power supply output unit 200, the first power supply voltage can be output at the first terminal of the first transistor Q1.

[0057] The specific structural relationship of the second power supply output unit in the voltage generation circuit provided in the embodiments of this application will be explained in detail below.

[0058] Figure 4 Please refer to the schematic diagram of the second power supply output unit in the voltage generation circuit provided in the embodiments of this application. Figure 4 The second power supply output unit 300 also includes: a second transistor Q2 and a third transistor Q3.

[0059] The first terminal of the first switch M1 is connected to the second terminal of the third switch M3 and the first terminal of the third transistor Q3 respectively, and outputs the second supply voltage. The second terminal of the first switch M1 is connected to the first terminal of the second transistor Q2. The control terminal of the first switch M1 is connected to the clock signal. The second and third terminals of the second transistor Q2 are grounded. The second and third terminals of the third transistor Q3 are grounded.

[0060] It should be noted that both the second transistor Q2 and the third transistor Q3 are bipolar transistors.

[0061] For the second power supply output unit 300, when the current source generated by the current generation unit 100 flows into the second power supply output unit 300, if the first switch M1 is turned on, the bias current generated by the current source flows through the second transistor Q2 and the third transistor Q3 respectively; if the first switch M1 is turned off, the bias current generated by the current source only flows through the third transistor Q3.

[0062] For the second supply voltage output from the first terminal of the third transistor Q3, when the first switch M1 is turned on, the second transistor Q2 divides the voltage, and the resulting voltage is a low potential voltage; correspondingly, when the first switch M1 is turned off, the second transistor Q2 does not divide the voltage, and the resulting voltage is a high potential voltage.

[0063] It should be noted that the first transistor Q1, the second transistor Q2, and the third transistor Q3 mentioned above can all be one transistor or multiple transistors in parallel. The number can be set according to actual needs, and no specific restrictions are imposed here.

[0064] The relationship between the second power supply voltage and the clock signal in the voltage generation circuit provided in the embodiments of this application will be explained in detail below.

[0065] Figure 5 For a schematic diagram illustrating the relationship between the second power supply voltage and the clock signal provided in this application embodiment, please refer to... Figure 5When the clock signal is high, the second power supply voltage is low; when the clock signal is low, the second power supply voltage is high.

[0066] The overall structural relationship of the voltage generation circuit provided in the embodiments of this application will be explained in detail below.

[0067] Figure 6 Please refer to the overall structural diagram of the voltage generation circuit provided in the embodiments of this application. Figure 6 The voltage generating circuit includes: a first switching transistor, a second switching transistor M2, a third switching transistor M3, a first transistor Q1, a second transistor Q2, and a third transistor Q3.

[0068] In this configuration, the control terminals of the second switch M2 and the third switch M3 are connected to a control voltage. The first terminal of the second switch M2 is connected to the first terminal of the third switch M3 and is connected to a power supply voltage. The second terminal of the second switch M2 is connected to the first power supply output unit 200, and the second terminal of the third switch M3 is connected to the second power supply output unit 300. The first terminal of the first transistor Q1 is connected to the second terminal of the second switch M2 and outputs a first power supply voltage. Both the second and third terminals of the first transistor Q1 are grounded. The first terminal of the first switch M1 is connected to the second terminals of the third switch M3 and the first terminal of the third transistor Q3, respectively, and outputs a second power supply voltage. The second terminal of the first switch M1 is connected to the first terminal of the second transistor Q2. The control terminal of the first switch M1 is connected to a clock signal. The second and third terminals of the second transistor Q2 are grounded, and the second and third terminals of the third transistor Q3 are grounded.

[0069] The working principle of this voltage generation circuit will be explained in detail below:

[0070] When the second switch M2 and the third switch M3 are turned on, the circuit starts to work. The second switch M2 and the third switch M3 each provide a current source of the same magnitude. For the first transistor Q1, the first supply voltage generated at its first terminal is a fixed value. When the first switch M1 is turned on, both the second transistor Q2 and the third transistor Q3 are connected to the circuit, and the second supply voltage output from the first terminal of the third transistor Q3 is at a low potential. When the first switch M1 is turned off, only the third transistor Q3 is connected to the circuit, and the second supply voltage output from the first terminal of the third transistor Q3 is at a high potential.

[0071] The following is a specific example to explain:

[0072] Assume that the third transistor Q3 and the first transistor Q1 are each one transistor (in practice, this can be extended to any number of transistors), and that the second transistor Q2 is n identical transistors connected in parallel. According to the current formula for a transistor... Therefore, when the current generated by the PMOS flows through n+1 transistors, the voltage generated by the circuit at point VR is: Similarly, when the clock signal CK is low, the voltage generated by the circuit at point VR is Therefore, it can be concluded that during the switching between high and low levels of the clock signal CK, the voltage at node VR also changes. BE2 and V BE2 Switch between ' and '.

[0073] Among them, I C I is the current flowing through the transistor. S For reverse saturation current, V BE V is the output supply voltage. T The thermal voltage of the circuit; VR point refers to the output voltage of the second supply voltage; V BE2 The output voltage when the second supply voltage is at a low potential, V BE2 ′ represents the output voltage when the second supply voltage is at a high potential.

[0074] Figure 7 Please refer to the schematic diagram of the bandgap reference device provided in the embodiments of this application. Figure 7 The bandgap reference device includes a voltage generation circuit 10 and a discrete voltage summing circuit 20. The voltage generation circuit 10 is connected to the discrete voltage summing circuit 20. The voltage generation circuit 10 is used to output a first supply voltage and a second supply voltage to the discrete voltage summing circuit 20. The discrete voltage summing circuit 20 is used to generate a bandgap reference voltage based on the first supply voltage and the second supply voltage.

[0075] Optionally, the discrete voltage summing circuit 20 can be any type of circuit that obtains the total voltage by summing the voltages through multiple discrete capacitors. The specific structure is not limited here, as long as it can generate a bandgap reference voltage based on the first supply voltage and the second supply voltage.

[0076] In a bandgap reference device provided in this application embodiment, the bandgap reference device may include a voltage generation circuit and a discrete voltage summing circuit. The voltage generation circuit 10 is connected to the discrete voltage summing circuit, and the voltage generation circuit is used to output a first supply voltage and a second supply voltage to the discrete voltage summing circuit. The discrete voltage summing circuit is used to generate a bandgap reference voltage based on the first supply voltage and the second supply voltage. The voltage generation circuit may include a current generation unit, a first power supply output unit, and a second power supply output unit. The output terminal of the current generation unit is connected to both the first power supply output unit and the second power supply output unit, and the current generation unit is used to generate a current source. The first power supply output unit is used to generate a first supply voltage based on the current source. The second power supply output unit includes a first switching transistor, and the second power supply output unit is used to generate a second supply voltage based on the current source. The first switching transistor controls the magnitude of the second supply voltage based on a clock signal, and the second supply voltage is a variable voltage. In this system, the same current generating unit provides power to both the first and second power supply output units, ensuring that the current sources are of the same magnitude and thus preventing current errors in the circuit. Furthermore, in the second power supply output unit, the first switching transistor is controlled to turn on and off based on a clock signal, thereby changing the magnitude of the second power supply voltage. The voltage difference generated by the on and off states of the first switching transistor allows for the output of the second power supply voltage that meets actual requirements, improving the stability of the output voltage and enabling the generation of a stable bandgap reference voltage based on the bandgap reference device.

[0077] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0078] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A voltage generating circuit characterized by comprising: include: Current generating unit, first power supply output unit and second power supply output unit; The second power supply output unit includes: a first switching transistor, a second transistor, and a third transistor; The current generating unit includes a second switch and a third switch. The control terminals of the second switch and the third switch are connected to a control voltage. The first terminal of the second switch and the first terminal of the third switch are connected to a power supply voltage. The second terminal of the second switch is connected to the first power supply output unit, and the second terminal of the third switch is connected to the second power supply output unit. The current generating unit is used to generate a current source. The first power supply output unit includes a first transistor, a first terminal of the first transistor is connected to the second terminal of the second switching transistor to generate a first power supply voltage according to the current source, and the second and third terminals of the first transistor are both grounded; The first terminal of the first switch is connected to the second terminal of the third switch and the first terminal of the third transistor respectively, and outputs a second supply voltage. The second terminal of the first switch is connected to the first terminal of the second transistor. The control terminal of the first switch is connected to a clock signal. The second and third terminals of the second transistor are grounded; The second and third terminals of the third transistor are grounded; The second power supply output unit is used to generate a second power supply voltage according to the current source, and to control the magnitude of the second power supply voltage based on a clock signal through the first switching transistor. The second power supply voltage is a variable voltage.

2. The voltage generating circuit of any one of claims 1, wherein, The first switching transistor is an N-type metal-oxide-semiconductor field-effect transistor.

3. The voltage generating circuit of claim 1, wherein, Both the second and third switching transistors are P-type metal-oxide-semiconductor field-effect transistors.

4. The voltage generating circuit of claim 1, wherein, The first transistor is a bipolar junction transistor (BJT).

5. The voltage generating circuit of claim 1, wherein, Both the second transistor and the third transistor are bipolar junction transistors (BJTs).

6. The voltage generating circuit as described in claim 1, characterized in that, When the clock signal is high, the first switch is turned on; when the clock signal is low, the first switch is turned off.

7. A bandgap reference device, characterized in that, The device includes a voltage generation circuit as described in any one of claims 1-6 and a discrete voltage summing circuit, wherein the voltage generation circuit is connected to the discrete voltage summing circuit, the voltage generation circuit is used to output the first supply voltage and the second supply voltage to the discrete voltage summing circuit, and the discrete voltage summing circuit is used to generate a bandgap reference voltage based on the first supply voltage and the second supply voltage.

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