A configurable constant-current constant-voltage power supply system

Abstract

The application relates to the technical field of power management, and discloses a configurable constant-current constant-voltage power supply system. The system comprises a voltage stabilizing unit, a current sampling unit, a voltage sampling unit, an analog-digital conversion unit and a processing unit. The current sampling unit converts output current into a voltage signal through a first resistor; the voltage sampling unit converts output voltage into a collectable voltage signal through a second resistor and a third resistor; the analog-digital conversion unit adopts two analog-digital converters to collect voltage signals of the first resistor and the third resistor respectively; the processing unit compares a constant-current value or a constant-voltage value set by a user and generates a control signal through a processing algorithm, and the output voltage of the voltage stabilizing unit is adjusted through a digital-analog converter. The application adopts a digital control scheme, a user can flexibly configure a working mode through software, has the advantages of high control precision, flexible parameter configuration and good stability, and is suitable for various application occasions requiring accurate current or voltage control.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power management, in particular, and particularly relates to a configurable constant current constant voltage power supply system. BACKGROUND

[0002] In the application scenarios of electronic device testing, battery charging and specific component driving, a direct current power supply is a kind of essential equipment. Its core functions usually include two modes of constant voltage output and constant current output. The constant voltage mode requires the power supply to maintain its output voltage stable at the set value when the load changes, which is the basic condition for most circuit operations. The constant current mode requires the power supply to maintain its output current stable at the set value when the load impedance changes, which is widely used in sensor power supply, battery charging, semiconductor device testing and other occasions.

[0003] Traditional direct current power supplies usually use analog circuits to realize constant voltage / constant current control. Two independent analog error amplifiers are usually designed, one for sampling and stabilizing the output voltage, and the other for sampling and stabilizing the output current. The outputs of the two amplifiers are connected through diodes and other components to control a common regulator. Under this architecture, whichever of the output voltage or the output current reaches the preset value first takes over the control right. Although the current analog control scheme has fast response speed, it also has inherent defects: first, the current set value is usually changed by adjusting the potentiometer or replacing the resistor, which has poor precision and flexibility and is difficult to control; second, the temperature drift and aging problems of analog components themselves will affect the long-term stability and precision; third, the function is single, and the switching logic between constant current and constant voltage modes is usually designed by hardware, which is complex and not easy to adjust.

[0004] Therefore, there is an urgent need for a constant current constant voltage power supply solution that is flexible in parameter configuration, good in stability and can be intelligently managed. To realize configurable constant current output with high precision and high stability. SUMMARY

[0005] Based on the deficiencies of the prior art, in view of the problem that the existing constant current constant voltage power supply regulation is complex, the embodiment of the present application provides a configurable constant current constant voltage power supply system, comprising: a voltage stabilizing unit, comprising an input end, an output end and a regulation end, for dynamically regulating the output voltage according to the regulation voltage; a current collecting unit, comprising a first resistor connected in series at the output end, for converting the output current into a sampleable voltage; a voltage collecting unit, comprising a second resistor and a third resistor connected in parallel at the output end, for converting the output voltage into a sampleable voltage; an analog-to-digital conversion unit, comprising a first analog-to-digital converter and a second analog-to-digital converter, the first analog-to-digital converter being used for collecting the voltage of the first resistor, and the second analog-to-digital converter being used for collecting the voltage of the third resistor; a processing unit, comprising a loop filter and a digital-to-analog converter, the loop filter being connected with the input end of the digital-to-analog converter, for receiving the collected voltages of the first analog-to-digital converter and the second analog-to-digital converter, and generating a control signal according to the pre-set constant voltage value or constant current value and sending the control signal to the digital-to-analog converter; and the output end of the digital-to-analog converter being connected with the regulation end of the voltage stabilizing unit, for converting the control signal into a regulation voltage and sending the regulation voltage to the voltage stabilizing unit for dynamic regulation.

[0006] Optionally, in the processing unit, the output voltage and output current of the power supply system are calculated according to the collected voltages of the first analog-to-digital converter and the second analog-to-digital converter, the loop filter compares the output voltage or the output current with the pre-set constant voltage value or constant current value to obtain a difference signal, and generates the control signal according to the difference signal.

[0007] Optionally, the constant voltage value and constant current value of the power supply system are set by software control.

[0008] Optionally, in the current collecting unit, one end of the first resistor is connected with the output end of the voltage stabilizing unit, and the other end is connected with the output of the power supply system.

[0009] Optionally, in the voltage collecting unit, the second resistor and the third resistor are connected in series, one end of the second resistor is connected with the output of the power supply system, the other end of the second resistor is connected with one end of the third resistor, and the other end of the third resistor is grounded.

[0010] Optionally, the voltage stabilizing unit is a linear voltage stabilizer.

[0011] The beneficial effects of the present application are:

[0012] 1. Flexible configuration, the set values of the output voltage and output current can be controlled and regulated by the voltage stabilizing unit, without the need to replace hardware components, so that the output configuration can be realized in a wide range and high precision, and the applicability and automation degree of the equipment are enhanced.

[0013] 2. Improve control accuracy, use high-precision ADC to directly sample the voltage, and accurately calculate the real-time current value through the formula. This method avoids the complexity and cost of traditional current detection, and the introduction of digital processing eliminates the inherent temperature drift and aging error of analog components, greatly improving the current control accuracy.

[0014] 3. Stability is enhanced, the application of digital loop filter can realize more complex and optimized control algorithm compared with traditional analog compensation network, so as to obtain excellent dynamic response performance under various load conditions. BRIEF DESCRIPTION OF DRAWINGS

[0015] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0016] Figure 1 is a configurable constant current constant voltage power supply system structure schematic diagram;

[0017] Among them, the above drawings include the following reference signs:

[0018] 1-Three-terminal voltage regulator, 2-First resistor, 3-Second resistor, 4-Third resistor, 5-First ADC (Analog-to-digital converter, Analog-to-digital converter), 6-Second ADC, 7-Loop filter, 8-DAC (digital-to-Analog converter, Digital-to-Analog converter). DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0020] It should be noted that the terms "first", "second", and the like in the description and in the claims of the present application as well as above-mentioned appended drawings are intended to distinguish similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of the terms so-termed as data can be interchanged where appropriate to enable the embodiments of the present application described herein to be implemented in other than the order depicted or described herein. Furthermore, the terms "comprise" and "have" and any variations thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a list of steps or units is not necessarily limited to those steps or units that are clearly listed, but can include other steps or units that are not clearly listed or inherent to such processes, methods, products, or apparatuses.

[0021] Figure 1 A configurable constant current constant voltage power supply system structure schematic diagram is shown, including a linear voltage regulator, which is a three-terminal voltage regulator 1 in the embodiments of the present application, without specific limitation. The three-terminal voltage regulator serves as a voltage regulating unit for dynamic regulation of output voltage, including an input end, an output end and a regulating end; a current collection unit, specifically a first resistor 2, one end of which is connected to the output end of the three-terminal voltage regulator, and the other end is output after passing through the first resistor, with a resistance value of R1; a voltage collection unit, specifically including a voltage dividing network composed of a second resistor 3 and a third resistor 4, the voltage collection unit being connected in parallel with the output end of the voltage regulator, and the second resistor and the third resistor being connected in series between them, one end of the second resistor being connected to the system output, the other end being connected to the third resistor, the other end of the third resistor being grounded, wherein the resistance values are R2 and R 3。

[0022] The system is also equipped with an analog-to-digital conversion unit, including two analog-to-digital converters, for converting the output current and output voltage of the current collection unit and the voltage collection unit into a sampleable voltage, specifically including a first ADC 5 and a second ADC 6, wherein the first ADC converts the output current of the first resistor into a collection voltage V2, and the second ADC converts the output voltage of the third resistor into a collection voltage V1, which are specifically ADC1 and ADC2 in the system.

[0023] The processing unit comprises a loop filter 7 and a DAC 8. In the loop filter, the output current and the output voltage are calculated according to the voltage values collected by the ADC 1 and the ADC 2. The constant current value or the constant voltage value required by the system is set in advance by software, and the difference signal is obtained by comparing the output current and the output voltage. After the difference signal is processed, the control signal is generated. The control signal can specifically include the voltage increase or the voltage decrease. After the control signal is generated by the loop filter, it is converted into the adjustment voltage by the DAC, and the current adjustment voltage is sent to the adjustment end of the three-terminal voltage regulator. The three-terminal voltage regulator dynamically adjusts the output voltage according to the adjustment voltage, thereby forming a closed-loop control, so that the output voltage or the output current is stabilized at the set value.

[0024] The constant current value or the constant voltage value in the loop filter is set flexibly according to the actual demand by software, so that the system can customize the current and the voltage for different application scenarios, and the high-precision digital power management is realized.

[0025] Specifically, in an embodiment, the constant voltage power supply adjustment is performed, and the voltage dividing network is set as the second resistor and the third resistor, specifically R2 and R3. First, the voltage V1 of R3 is collected by the ADC 2, and then the output voltage is calculated by the formula (1) of the voltage dividing network.

[0026] (1)

[0027] wherein, Vout is the output voltage of the system, V3 is the voltage value of the third resistor, and R2 and R3 are the resistance values of the second resistor and the third resistor.

[0028] At this time, the constant voltage V set of the system is set in advance by software. The loop filter calculates the difference signal between the constant voltage and the output voltage in real time by the formula (2):

[0029] (2)

[0030] wherein, Vdiff is the difference signal between the constant voltage and the output voltage, V0 is the constant voltage set in advance.

[0031] When V e > 0V, the actual voltage is too low and does not reach the voltage value set in advance, and the control signal for increasing the output voltage of the three-terminal voltage regulator needs to be sent. When V e < 0V, the actual voltage is too high and exceeds the voltage value set in advance, and the control signal for reducing the output voltage of the three-terminal voltage regulator needs to be sent.

[0032] ​The current control signal is sent to the DAC, which converts the digital control signal into an analog regulating voltage to drive the three-terminal voltage regulator to adjust , until = , at which time the output voltage reaches the constant voltage value set by the user.

[0033] In another embodiment, constant current source regulation is performed, first by ADC2 to collect the voltage V1, and then by formula (1) to calculate the output voltage of the system .

[0034] ADC1 collects the voltage V2, and the output current flows through the first resistor R1 to generate a voltage difference, and the voltage drop is calculated according to formula (3):

[0035] (3)

[0036] wherein, is the voltage drop of the first resistor, is the voltage of the first resistor.

[0037] At this time, the output current is calculated according to formula (4):

[0038] (4)

[0039] wherein, is the output current of the power supply system, is the resistance of the first resistor, which is very small in this embodiment and can be ignored.

[0040] A constant current I set is set in advance, and the loop filter calculates the difference signal between the constant current and the output current according to formula (5):

[0041] (5)

[0042] wherein, is the difference signal between the constant current and the output current, is the constant current set in advance.

[0043] The difference signal is processed by the loop filter, and if > 0, the actual current is less than the set target current, and the current is insufficient, at which time a control signal is sent to reduce the output voltage of the three-terminal voltage regulator, and if < 0, the actual current is greater than the set target current, and the current is over-limit, at which time a control signal is sent to increase the output voltage of the three-terminal voltage regulator to limit the current.

[0044] The current control signal is sent to the DAC, and the DAC converts the digital control signal into an analog regulating voltage to drive the voltage regulator to adjust , until = I set At this time, the output current reaches the constant current value set by the user.

[0045] The above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0046] In the above-mentioned embodiments of the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0047] In the several embodiments provided by the present application, it should be understood that the disclosed technology can be implemented in other ways. Of course, the unit described as the division is only a description of logical function division, and there can be another division manner in actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling or direct coupling or communication connection between each other can be indirect coupling or communication connection through some interface, unit or module, and can be electrical or other forms.

[0048] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0049] The above-mentioned is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should be regarded as the protection scope of the present application.

Claims

1. A configurable constant current constant voltage power supply system, characterized by, The application relates to a power supply system, comprising: a voltage stabilizing unit, which is a linear voltage stabilizer, comprising an input end, an output end and an adjusting end, and is used for dynamically adjusting an output voltage according to an adjusting voltage; a current collecting unit, comprising a first resistor connected in series at the output end, one end of the first resistor being connected to the output end of the voltage stabilizing unit, and the other end being connected to the output of the power supply system, and being used for converting the output current into a sampleable voltage; a voltage collecting unit, comprising a second resistor and a third resistor connected in parallel at the output end, the second resistor and the third resistor being connected in series, one end of the second resistor being connected to the output of the power supply system, the other end of the second resistor being connected to one end of the third resistor, and the other end of the third resistor being grounded, and being used for converting the output voltage into a sampleable voltage; an analog-digital conversion unit, comprising a first analog-digital converter and a second analog-digital converter, the first analog-digital converter being used for collecting the voltage of the first resistor, and the second analog-digital converter being used for collecting the voltage of the third resistor; a processing unit, comprising a loop filter and a digital-analog converter, the loop filter being connected to the input end of the digital-analog converter, and being used for receiving the collected voltages of the first analog-digital converter and the second analog-digital converter, the loop filter calculating the output voltage and the output current of the power supply system according to the collected voltages of the first analog-digital converter and the second analog-digital converter, comparing the output voltage or the output current with a pre-set constant voltage or constant current to obtain a difference signal, processing the difference signal to generate a control signal, and sending the control signal to the digital-analog converter; the output end of the digital-analog converter being connected to the adjusting end of the voltage stabilizing unit, and being used for converting the control signal into an adjusting voltage, and sending the adjusting voltage to the voltage stabilizing unit for dynamic adjustment; wherein the dynamic adjustment of the voltage stabilizing unit is controlled by software, and the power supply system is adjusted to the constant current or the constant voltage.

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