Direct-current stabilized power supply circuit and measuring equipment

Abstract

According to the direct-current stabilized power supply circuit and the measuring equipment, the voltage stabilizing module is additionally arranged at the output end of the switching power supply module, the voltage stabilizing module can carry out voltage stabilizing processing on a second direct-current electric signal output by the switching power supply module, and dynamic feedback adjustment is carried out through the control adjusting module; a third direct-current electric signal finally output by the direct-current stabilized power supply circuit is high in precision, small in voltage ripple and low in noise, in addition, dynamic feedback adjustment is carried out on a second direct-current electric signal output by the switching power supply module through the control adjustment module based on the leakage voltage of the second switching device, and the reliability of the direct-current stabilized power supply circuit is improved. And the voltage difference between the second direct current signal and the third direct current signal fluctuates up and down within the preset range of the leakage voltage of the second switching device, so that the circuit can have relatively high energy conversion efficiency.

Description

Technical Field

[0001] The present application relates to the field of direct current voltage regulation technology, and in particular to a direct current voltage regulated power supply circuit and a measuring device. Background Art

[0002] The standby time and usage time of measuring equipment (such as oscilloscopes, spectrum analyzers, etc.) are key indicators for considering the energy-saving performance of measuring equipment. At present, commonly used energy-saving technologies can be divided into static energy-saving technologies and dynamic energy-saving technologies. Among them, static energy-saving technologies are to adapt to low-power application scenarios by turning off the clock, power supply or functional modules of different components inside the chip of the measuring equipment; dynamic energy-saving technologies are to dynamically adjust the operating frequency and voltage of the processor in the measuring equipment according to the changes in computing resources during the operation of the chip in the measuring equipment, so as to achieve the purpose of energy saving.

[0003] Dynamic energy-saving technology is often used in DC switching power supplies in measuring equipment. Some technologies use PWM (Pulse Width Modulation), DAC (Digital to Analog Converter), and digital potentiometers to control the feedback voltage end of the power management chip. Digital DC-DC regulated power supplies are generally composed of inductors, capacitors, diodes, transistors, and control circuits. The PWM signal is adjusted through the internal control circuit to convert the input DC voltage into a constant DC voltage output. The DC-DC regulated power supply has a high energy conversion efficiency, but the output end of the power supply has a high voltage ripple and switching noise.

[0004] In summary, current measurement equipment has certain requirements for DC regulated power supplies with lower voltage ripple and switching noise and higher energy conversion efficiency. Summary of the invention

[0005] The present application provides a DC regulated power supply circuit and a measuring device, which solve the problem of how to achieve higher energy conversion efficiency, lower voltage ripple and lower noise.

[0006] According to the first aspect, an embodiment provides a DC regulated power supply circuit, comprising: A switching power supply module, comprising a first switching device; the switching power supply module is used to perform a first voltage conversion process on an input first DC power signal and output a required second DC power signal by turning on or off the first switching device; A voltage stabilizing module, comprising a second switching device; the voltage stabilizing module is used to perform a second voltage conversion process on the second DC power signal obtained from the switching power supply module based on the control electrode voltage of the second switching device, and output a required third DC power signal; a control and regulation module, connected to the switching power supply module to form a first control closed loop, for generating a first control electrical signal based on the second DC power signal, the third DC power signal and the leakage voltage of the second switching device, and controlling the first switching device in the switching power supply module to be turned on or off based on the first control electrical signal; The control and regulation module is connected to the voltage stabilizing module, and the switching power supply module, the voltage stabilizing module and the control and regulation module form a second control closed loop that is synchronously controlled with the first control closed loop; the control and regulation module is used to generate a second control electrical signal based on the voltage difference between the third DC signal and the preset target voltage value, and control the voltage stabilizing module to obtain the control electrode voltage of the second switching device based on the second control electrical signal, so as to perform a second voltage conversion process on the second DC signal to obtain a third DC signal that is close to the preset target voltage value; The first voltage conversion process is different from the second voltage conversion process, and the voltage difference between the second DC signal and the third DC signal fluctuates within a preset range of the leakage voltage of the second switching device.

[0007] In one embodiment, the control and regulation module includes: a controller, a first digital-to-analog converter, a first analog-to-digital converter, a second digital-to-analog converter, and a second analog-to-digital converter; The second analog-to-digital converter is connected to the output end of the voltage stabilizing module, and is used to convert the third DC signal into a third digital signal and output the third digital signal; The controller is connected to the second analog-to-digital converter, and is used to obtain the third digital signal, and determine the second control digital signal based on a voltage difference between the third digital signal and the preset target voltage value; The second digital-to-analog converter is connected to the controller and is used to convert the second control digital signal into a second control electrical signal; The first analog-to-digital converter is connected to the output end of the switching power supply module, and is used to convert the second DC signal into a second digital signal and output the second digital signal; The controller is connected to the first analog-to-digital converter, and is used to obtain the second digital signal, and determine the first control digital signal based on the second DC signal, the third DC signal and the leakage voltage of the second switch device; The first digital-to-analog converter is connected to the controller, and is used for converting the first control digital signal into a first control electrical signal.

[0008] In one embodiment, it also includes: The control and regulation module is used to determine the leakage voltage of the second switch device according to the target output voltage of the switch power supply module and the preset target voltage value; or, The control and regulation module is used to obtain the load current of the DC regulated power supply circuit, and determine the leakage voltage of the second switch device according to the load current and a preset proportional factor.

[0009] In one embodiment, it also includes: The load current detection module is connected to the output end of the voltage stabilizing module and is used to detect the current at the output end of the voltage stabilizing module to obtain the load current of the DC regulated power supply circuit.

[0010] In one embodiment, the load current detection module includes: A detection resistor, one end of which is connected to the output end of the voltage stabilizing module, and the other end of which is used to output the load current; A voltage difference detection unit, having a first input end and a second input end, wherein the first input end is connected to one end of the detection resistor, and the second input end is connected to the other end of the detection resistor, and the voltage difference amplification unit is used to obtain the voltage difference between the two ends of the detection resistor and output a voltage difference signal; the voltage difference signal is used to characterize the magnitude of the load current; A third analog-to-digital converter is connected to the output end of the voltage difference detection unit, and is used for converting the voltage difference signal into a digital voltage difference signal, and outputting the digital voltage difference signal to the controller.

[0011] In one embodiment, the voltage difference detection unit is further used to amplify the acquired voltage difference signal across the detection resistor.

[0012] In one embodiment, it further includes: a first signal processing module; the first signal processing module includes: a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C11, a capacitor C12, a capacitor C13 and an inductor L11; One end of the resistor R13 is connected to the output end of the first digital-to-analog converter, the other end of the resistor R13 is connected to one end of the resistor R11 and one end of the resistor R12, the other end of the resistor R11 is connected to the output end of the switching power module, one end of the capacitor C11 is connected to the input end of the switching power module, the other end of the capacitor C11 is connected to the ground, the end of the resistor R13 connected to the resistor R11 and the resistor R12 is used to output the first control electrical signal to the feedback end of the switching power module, and the other end of the resistor R12 is grounded; One end of the resistor R14 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the ground, the other end of the resistor R14 is connected to one end of the capacitor C13, and the other end of the capacitor C13 is connected to the ground, wherein the end of the resistor R14 connected to the resistor R15 is used to connect to the input end of the first analog-to-digital converter, and the end of the resistor R14 connected to the capacitor C13 is used to connect to the output end of the switching power supply module; One end of the inductor L11 is connected to the output end of the switching power supply module, the other end of the inductor L11 is connected to one end of the capacitor C12, the other end of the capacitor C12 is connected to the ground, and the end of the inductor L11 connected to the capacitor C12 is used to output a second DC signal.

[0013] In one embodiment, it further includes: a second signal processing module; the second signal processing module includes: a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a capacitor C21, a capacitor C22 and a capacitor C23; One end of the resistor R23 is connected to the output end of the second digital-to-analog converter, the other end of the resistor R23 is connected to one end of the resistor R21 and one end of the resistor R22, the other end of the resistor R21 is connected to the output end of the voltage stabilizing module, one end of the capacitor C21 is connected to the input end of the voltage stabilizing module, the other end of the capacitor C21 is connected to the ground, the end of the resistor R23 connected to the resistor R21 and the resistor R22 is used to output the second control electrical signal to the feedback end of the voltage stabilizing module, and the other end of the resistor R22 is grounded; One end of the resistor R24 ​​is connected to one end of the resistor R25, the other end of the resistor R25 is connected to the ground, the other end of the resistor R24 ​​is connected to one end of the capacitor C23, and the other end of the capacitor C23 is connected to the ground, wherein the end of the resistor R24 ​​connected to the resistor R25 is used to connect to the input end of the second analog-to-digital converter, and the end of the resistor R24 ​​connected to the capacitor C23 is used to connect to the output end of the voltage stabilizing module; One end of the capacitor C22 is connected to the output end of the voltage stabilizing module, and the other end of the capacitor C22 is connected to the ground.

[0014] In one embodiment, the DC regulated power supply circuit has at least an initial state; wherein, In the initial state: The second control electrical signal is determined according to the following expression: V ctr2 = V ref2 (1+R 23 / R 21 +R 23 / R 22 ) -V_out (R 23 / R 21 ); Among them, R21 is the resistance value of resistor R21, R 22 is the resistance value of resistor R22, R 23 is the resistance value of resistor R23, V ctr2 is the voltage corresponding to the second control electrical signal, V_out is the preset target voltage value, V ref2 It is the reference voltage of the voltage regulator module; The first control electrical signal is determined according to the following expression: V ctr1 = V ref1 (1+R 13 / R 11 +R 13 / R 12 )- (V_out +V dropout +σ) (R 13 / R 11 ); Among them, R 13 is the resistance value of resistor R13, R 11 is the resistance value of resistor R11, R 12 is the resistance value of resistor R12, V ctr1 is the voltage corresponding to the first control electrical signal, V_out is the preset target voltage value, V dropout is the leakage voltage, σ is the correction margin factor of the leakage voltage, V ref1 It is the reference voltage of the switching power supply module.

[0015] In one embodiment, it also includes: A serial interface bus is used for communication between the controller and the first digital-to-analog converter, the first analog-to-digital converter, the second digital-to-analog converter, and the second analog-to-digital converter.

[0016] According to the second aspect, an embodiment provides a measuring device, comprising: A conversion circuit, used for performing DC conversion on an input AC signal and outputting a first DC signal; A DC regulated power supply circuit, wherein the DC regulated power supply circuit is a circuit as described in any one of the above embodiments, and is used to perform voltage conversion processing on the first DC signal to output a third DC signal; One or more load circuits, the third DC power signal is used to provide a DC power signal to the load circuit.

[0017] According to the DC regulated power supply circuit and measuring device of the above-mentioned embodiment, since a regulated voltage module is added to the output end of the switching power supply module, the regulated voltage module can perform voltage stabilization processing on the second DC power signal output by the switching power supply module, and perform dynamic feedback regulation through the control and regulation module, so that the third DC power signal finally output by the DC regulated power supply circuit has high precision, small voltage ripple and low noise. In addition, the control and regulation module performs dynamic feedback regulation on the second DC power signal output by the switching power supply module based on the leakage voltage of the second switching device, so that the voltage difference between the second DC power signal and the third DC power signal fluctuates within a preset range of the leakage voltage of the second switching device, so that the circuit can have a higher energy conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a DC regulated power supply circuit according to an embodiment of the present application; Figure 2 A schematic diagram of the structure of a switching power supply module according to an embodiment; Figure 3 A schematic diagram of the structure of a voltage stabilizing module according to an embodiment; Figure 4 A schematic diagram of the structure of a control and regulation module according to an embodiment; Figure 5 A circuit diagram of a first signal processing module and a second signal processing module according to an embodiment; Figure 6 is a schematic diagram of the relationship between the leakage voltage and the load current; Figure 7 It is a structural schematic diagram of a DC regulated power supply circuit of another embodiment; Figure 8 A structural diagram of a load current detection module according to an embodiment; Fig. 9 A flow chart of a dynamic voltage regulation method for a DC regulated power supply circuit according to an embodiment; Fig.10 This is a schematic diagram of the structure of the measuring device according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] The present application is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0020] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0021] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0022] The power supply technology for measuring equipment usually requires lower voltage ripple and noise. Some voltage regulators can meet the above requirements. For example, the switching device in the LDO voltage regulator operates in the linear range, has good stability, fast load response, and the output voltage signal has small ripple and low noise. However, when the voltage difference between the input voltage and the output voltage of the LDO voltage regulator is large, the voltage signal loses a lot of energy on the LDO voltage regulator, resulting in low energy conversion efficiency of the LDO voltage regulator.

[0023] In response to the above problems, an embodiment of the present application provides a DC regulated power supply circuit. First, a voltage stabilizing module is added to the output end of the switching power supply module to reduce the voltage ripple and noise of the third DC power signal output by the DC regulated power supply circuit; secondly, the voltage stabilizing module is dynamically feedback-regulated by the control and regulation module, so that the third DC power signal output by the DC regulated power supply circuit can approach a preset target voltage value, thereby improving the output accuracy; finally, the second DC power signal output by the switching power supply module is dynamically feedback-regulated by the control and regulation module, so that the voltage difference between the second DC power signal and the third DC power signal fluctuates within a preset range of the leakage voltage of the second switching device in the voltage stabilizing module, thereby ensuring a high energy conversion efficiency.

[0024] Please refer to Figure 1 The embodiment of the present application provides a DC regulated power supply circuit, comprising: a switching power supply module 101, a voltage regulated module 102 and a control and regulation module 103, wherein the input end of the switching power supply module 101 is used to obtain an input first DC signal Vin, the output end of the switching power supply module 101 is connected to the input end of the voltage regulated module 102, the switching power supply module 101 inputs the output second DC signal Vmid to the input end of the voltage regulated module 102, and the output end of the voltage regulated module 102 outputs a third DC signal Vout to a load circuit to power the load circuit; the input end of the control and regulation module 103 is respectively connected to the output end of the switching power supply module 101 and the output end of the voltage regulated module 102, the output end of the control and regulation module 103 is respectively connected to the feedback end of the switching power supply module 101 and the feedback end of the voltage regulated module 102, the feedback end of the switching power supply module 101 is used to control the conduction or shutdown of the first switching device in the switching power supply module 101, and the feedback end of the voltage regulated module 102 is used to control the control electrode voltage of the second switching device in the voltage regulated module 102. The connection between the control and regulation module 103 and the switching power module 101 forms a first control closed loop, and the connection between the control and regulation module 103 and the switching power module 101 and the voltage stabilizing module 102 forms a second control closed loop that is synchronously controlled with the first control closed loop.

[0025] The switching power supply module 101 includes a first switching device, and the switching power supply module 101 is used to control the on or off of the first switching device to perform a first voltage conversion process on an input first DC signal Vin and output a required second DC signal Vmid.

[0026] For some examples, please refer to Figure 2The switching power supply module 101 is a DC-DC switching power supply chip, which includes a first switching device 201, a first control logic circuit 202, a first comparator 203 and a first reference voltage generating circuit 204, wherein the first input end of the first comparator 203 is used to obtain a first control electrical signal Vctrl input from the outside, the second input end of the first comparator 203 is connected to the output end of the first reference voltage generating circuit 204, and is used to obtain a reference voltage Vref1 of the switching power supply module 101, the output end of the first comparator 203 is connected to the input end of the first control logic circuit 202, and the first The output end of the control logic circuit 202 is connected to the first switch device 201, wherein the first switch device 201 may include a first switch tube Q1 and a second switch tube Q2, the output end of the first control logic circuit 202 is connected to the control electrode of the first switch tube Q1 and the control electrode of the second switch tube Q2, the first electrode of the first switch tube Q1 is connected to the input first DC signal Vin, the second electrode of the first switch tube Q1 is connected to the first electrode of the second switch tube Q2, the second electrode of the second switch tube Q2 is connected to the ground, and one electrode connected to the first switch tube Q1 and the second switch tube Q2 is used to output the second DC signal Vmid. The above-mentioned first switch tube Q1 and the second switch tube Q2 are the first switch devices.

[0027] Based on the above circuit, it can be known that after comparing the first control electrical signal Vctrl inputted at the first input terminal of the first comparator 203 with the reference voltage Vref1 of the switching power supply module 101 inputted at its second input terminal, a first control voltage difference can be obtained. The first control logic circuit 202 outputs a PWM control signal with a duty cycle corresponding to the first control electrical signal Vctrl based on the inputted first control voltage difference, so as to control the conduction or shutoff of the first switch tube Q1 and the second switch tube Q2 in the first switch device 201, thereby controlling the voltage of the second DC signal Vmid outputted finally. It should be noted that the conduction and shutoff states of the first switch tube Q1 and the second switch tube Q2 are mutually exclusive, that is, when the first switch tube Q1 is turned on, the second switch tube Q2 is turned off, and when the first switch tube Q1 is turned off, the second switch tube Q2 is turned on.

[0028] The voltage stabilizing module 102 includes a second switching device, and the voltage stabilizing module 102 is used to control the control electrode voltage of the second switching device to perform a second voltage conversion process on the second DC signal Vmid, and output a third DC signal Vout of the required voltage. The third DC signal Vout is used to provide a DC power signal to the load circuit of the DC regulated power supply circuit.

[0029] For some examples, please refer to Figure 3The voltage stabilizing module 102 may be an LDO voltage stabilizing chip, which includes a second switch device 301, a second control logic circuit 302, a second comparator 303 and a second reference voltage generating circuit 304, wherein a first input end of the second comparator 303 is used to obtain an externally input second control electrical signal Vctr2, a second input end of the second comparator 303 is connected to an output end of the second reference voltage generating circuit 304, and is used to obtain a reference voltage Vref2 of the voltage stabilizing module 102, an output end of the second comparator 303 is connected to an input end of the second control logic circuit 302, and an output end of the second control logic circuit 302 is connected to a second switch device 301, wherein the second switch device 301 may include a third switch tube Q3, an output end of the second control logic circuit 302 is connected to a control electrode of the third switch tube Q3, a first electrode of the third switch tube Q3 is connected to an input second DC signal Vmid, and a second electrode of the third switch tube Q3 is used to output a third DC signal Vout. Among them, the third switch tube Q3 is a power tube PMOS, in which the control electrode is the gate, the first electrode is the source, and the second electrode is the drain. The third switch tube Q3 is always in the on state, and the voltage stabilizing module 102 controls the voltage between the source and the gate of the power tube PMOS to output the third DC signal Vout of the required voltage. Since the third switch tube Q3 needs to be kept in the on state, the source voltage needs to be always greater than the gate voltage, and the source voltage is also always greater than the voltage of the third DC signal Vout, that is, the minimum voltage difference is the leakage voltage of the third switch tube Q3. The above-mentioned third switch tube Q3 is a second switch device.

[0030] The specific regulation process of the voltage stabilizing module 102 is as follows: when the voltage of Vout drops due to load changes or other reasons, if the output of the regulating module 103 is not controlled, the potential of the first input terminal of the second comparator 303 drops, and the voltage difference between the potential of the first input terminal of the second comparator 303 and the potential of the second input terminal (Vref2) increases, and the second comparator 303 will reduce the output accordingly, so that the gate potential of the third switch tube Q3 drops, and the Vs voltage remains unchanged, thereby increasing the voltage difference of the voltage |Vgs| between the gate and the source, and the current Isd between the gate and the drain will increase. The increase in the output current Isd will cause Vout to rise, completing a feedback control, so that Vout returns to the normal potential.

[0031] Based on the above circuit, it can be known that after adding the feedback adjustment of the control and regulation module 103, the second control electrical signal Vctr2 inputted at the first input terminal of the second comparator 303 is compared with the reference voltage Vref2 of the voltage regulating module 102 inputted at its second input terminal, and a second control voltage difference can be obtained. The second control logic circuit 302 outputs a PWM control signal with a duty cycle corresponding to the second control electrical signal Vctr2 based on the input second control voltage difference, so as to control the control electrode voltage of the third switch tube Q3 in the second switch device 301, thereby more accurately controlling the voltage of the third DC signal Vout finally outputted.

[0032] The first control electrical signal Vctr1 and the second control electrical signal Vctr2 input to the feedback ends of the switching power supply module 101 and the voltage stabilizing module 102 are output by the control and regulation module 103 .

[0033] The control and regulation module 103 is used to generate a second control electrical signal based on the voltage difference between the third DC signal and the preset target voltage value, and to control the voltage stabilization module to obtain the control electrode voltage of the second switching device based on the second control electrical signal, so as to perform a second voltage conversion process on the second DC signal to obtain a third DC signal that is close to the preset target voltage value.

[0034] The control and regulation module 103 is used to generate a first control electrical signal based on the second DC signal, the third DC signal and the leakage voltage of the second switch device, and control the first switch device in the switch power supply module 101 to turn on or off based on the first control electrical signal.

[0035] Among them, the voltage difference between the second DC signal and the third DC signal fluctuates within a preset range of the leakage voltage of the second switching device, so that the voltage difference between the input voltage and the output voltage of the voltage stabilizing module 102 is minimized, thereby ensuring a high energy conversion efficiency, and realizing high-precision control of the output signal (the third DC signal Vout) through the control and regulation module 103, and the voltage ripple and noise are small.

[0036] For some examples, please refer to Figure 4 The control and regulation module 103 includes: a controller MCU, a first digital-to-analog converter DAC1, a first analog-to-digital converter ADC1, a second digital-to-analog converter DAC2, and a second analog-to-digital converter ADC2; the controller MCU is connected to the first digital-to-analog converter DAC1, the first analog-to-digital converter ADC1, the second digital-to-analog converter DAC2, and the second analog-to-digital converter ADC2. In one embodiment, the communication connection can be performed through a serial interface bus SPI / I2C. Wherein: The second analog-to-digital converter ADC2 is connected to the output end of the voltage stabilizing module 102 , and the second analog-to-digital converter ADC2 is used for converting the third DC signal Vout into a third digital signal and outputting the third digital signal.

[0037] The controller MCU is connected to the second analog-to-digital converter ADC2. The controller MCU is used to obtain the third digital signal and determine the second control digital signal based on the voltage difference between the third digital signal and a preset target voltage value.

[0038] The second digital-to-analog converter DAC2 is connected to the controller MCU, and the second digital-to-analog converter DAC2 is used to convert the second control digital signal into a second control electrical signal Vctr2.

[0039] The first analog-to-digital converter ADC1 is connected to the output end of the switching power supply module 101 . The first analog-to-digital converter ADC1 is used to convert the second direct current signal Vmid into a second digital signal and output the second digital signal.

[0040] The controller MCU is connected to the first analog-to-digital converter ADC1, and is used to obtain the second digital signal, and determine the first control digital signal based on the second digital signal, the third digital signal and the leakage voltage of the second switch device.

[0041] The first digital-to-analog converter DAC1 is connected to the controller MCU, and the first digital-to-analog converter DAC1 is used to convert the first control digital signal into a first control electrical signal Vctr1.

[0042] In some embodiments, the switching power supply module 101 and the voltage stabilizing module 102 both have some peripheral processing circuits. Figure 5 , further comprising: a first signal processing module and a second signal processing module, the first signal processing module being a peripheral processing circuit of the switching power supply module 101 , and the second signal processing module being a peripheral processing circuit of the voltage stabilizing module 102 .

[0043] In some embodiments, the first signal processing module includes: a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C11, a capacitor C12, a capacitor C13 and an inductor L11; wherein: One end of the resistor R13 is connected to the output end of the first digital-to-analog converter DAC1, the other end of the resistor R13 is connected to one end of the resistor R11 and one end of the resistor R12, the other end of the resistor R11 is connected to the output end of the switching power module 101, one end of the capacitor C11 is connected to the input end of the switching power module 101, the other end of the capacitor C11 is connected to the ground, and the end of the resistor R13 connected to the resistor R11 and the resistor R12 is used to output the first control electrical signal Vctr1 to the feedback end of the switching power module 101. Among them, the resistor R11 and the resistor R12 form a voltage divider circuit, which is used to adjust the voltage of the signal input to the feedback end of the switching power module 101, the resistor R13 has the function of voltage division and current limiting, and the capacitor C11 can stabilize the voltage of the signal input to the input end of the switching power module 101.

[0044] One end of the resistor R14 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the ground, the other end of the resistor R14 is connected to one end of the capacitor C13, the other end of the capacitor C13 is connected to the ground, wherein the end of the resistor R14 connected to the resistor R15 is used to connect to the input end of the first analog-to-digital converter ADC1, and the end of the resistor R14 connected to the capacitor C13 is used to connect to the output end of the switching power supply module 101. The resistor R14 and the resistor R15 are used to divide the second DC signal Vmid output by the switching power supply module 101 and output it to the first analog-to-digital converter ADC1, and the capacitor C13 is used to stabilize the voltage of the signal input to the first analog-to-digital converter ADC1.

[0045] One end of the inductor L11 is connected to the output end of the switching power supply module 101, the other end of the inductor L11 is connected to one end of the capacitor C12, the other end of the capacitor C12 is connected to the ground, and the end of the inductor L11 connected to the capacitor C12 is used to output the second DC signal Vmid. The inductor L11 and the capacitor C12 form an LC filter circuit, which can stably output the second DC signal Vmid.

[0046] In some embodiments, the second signal processing module includes: a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a capacitor C21, a capacitor C22 and a capacitor C23; wherein: One end of the resistor R23 is connected to the output end of the second digital-to-analog converter DAC2, the other end of the resistor R23 is connected to one end of the resistor R21 and one end of the resistor R22, the other end of the resistor R21 is connected to the output end of the voltage stabilizing module 102, one end of the capacitor C21 is connected to the input end of the voltage stabilizing module 102, the other end of the capacitor C21 is connected to the ground, and one end of the resistor R23 connected to the resistor R21 and the resistor R22 is used to output the second control electrical signal Vctr2 to the feedback end of the voltage stabilizing module 102. Among them, the resistor R21 and the resistor R22 form a voltage divider circuit for adjusting the voltage of the signal input to the feedback end of the voltage stabilizing module 102, the resistor R23 has the function of voltage division and current limiting, and the capacitor C21 can stabilize the voltage of the signal input to the input end of the voltage stabilizing module 102.

[0047] One end of the resistor R24 ​​is connected to one end of the resistor R25, the other end of the resistor R25 is connected to the ground, the other end of the resistor R24 ​​is connected to one end of the capacitor C23, and the other end of the capacitor C23 is connected to the ground, wherein the end of the resistor R24 ​​connected to the resistor R25 is used to connect to the input end of the second analog-to-digital converter ADC2, and the end of the resistor R24 ​​connected to the capacitor C23 is used to connect to the output end of the voltage stabilizing module 102; wherein the resistor R24 ​​and the resistor R25 are used to divide the third DC signal Vout output by the voltage stabilizing module 102 and output it to the second analog-to-digital converter ADC2, and the capacitor C23 is used to stabilize the voltage of the signal input to the second analog-to-digital converter ADC2.

[0048] One end of the capacitor C22 is connected to the output end of the voltage stabilizing module 102 , and the other end of the capacitor C22 is connected to the ground. The capacitor C22 is used to stabilize the voltage output by the voltage stabilizing module 102 .

[0049] In some embodiments, the dropout voltage of the second switching device can be determined by the following two methods: (1) According to the target output voltage of the switching power supply module 101 and the preset target voltage value, the leakage voltage of the second switching device is determined; since the leakage voltage V dropout It should not be less than the difference between the input voltage and the output voltage of the voltage regulator module 102. In order to obtain greater energy conversion efficiency and meet the minimum voltage drop requirement of the voltage regulator module 102, V dropout =V_mid-V_out, wherein V_mid is the target output voltage of the switching power supply module 101, that is, the target value of Vmid, and V_out is the preset target voltage value, that is, the target value of Vout.

[0050] In one embodiment, in actual engineering application, V dropout The correction margin factor σ can be appropriately increased to ensure circuit stability, V dropout =V_mid-V_out-σ.

[0051] (2) According to the load current I load and a preset proportional factor K to determine the leakage voltage of the second switching device; Figure 6 As shown, the dropout voltage V dropout (Dropout Volvage) varies with load current I load (Output Current) changes in direct proportion, and the leakage voltage V dropout =K × I load .

[0052] The above method (2) requires the load current I load For testing, please refer to Figure 7 In some embodiments, the load current detection module 104 connected to the output end of the voltage stabilizing module 102 can detect the current at the output end of the voltage stabilizing module 102 to obtain the load current I of the DC regulated power supply circuit. load .

[0053] Please refer to Figure 8 In one embodiment, the load current detection module 104 includes: a detection resistor Rsensor, a voltage difference detection unit 701 and a third analog-to-digital converter ADC3; one end of the detection resistor Rsensor is connected to the output end of the voltage stabilizing module 102, and the other end is used to output the load current I load The voltage difference detection unit 701 has a first input terminal and a second input terminal, the first input terminal of the voltage difference detection unit 701 is connected to one end of the detection resistor Rsensor, the second input terminal of the voltage difference detection unit 701 is connected to the other end of the detection resistor Rsensor, and the voltage difference amplification unit 701 is used to obtain the voltage difference between the two ends of the detection resistor Rsensor and output a voltage difference signal, wherein the voltage difference signal is used to characterize the magnitude of the load current; the third analog-to-digital converter ADC3 is connected to the output terminal of the voltage difference detection unit 701, and is used to convert the voltage difference signal into a digital voltage difference signal, and output the digital voltage difference signal to the controller MCU.

[0054] Since the voltage difference across the detection resistor Rsensor is very small, directly outputting the detected voltage difference to the controller MCU for detection may not be sufficient in terms of detection accuracy of the controller MCU. Therefore, in one embodiment, the voltage difference detection unit 701 is also used to amplify the acquired voltage difference signal across the detection resistor, and send the amplified voltage difference signal to the controller MCU via the third analog-to-digital converter ADC3.

[0055] In one embodiment, the voltage difference amplification unit 701 may include a third comparator 7011, a fourth switch tube Q4 and a mirror image constant current source (Current Mirror) 7022, wherein the first input end of the third comparator 7011 is connected to one end of the detection resistor Rsensor through a resistor R31, the second input end of the third comparator 7011 is connected to the other end of the detection resistor Rsensor through a resistor R32, the output end of the third comparator 7011 is connected to the control electrode of the fourth switch tube Q4, the first electrode of the fourth switch tube Q4 is connected to the first input end of the third comparator 7011, the second electrode of the fourth switch tube Q4 is connected to the input end of the mirror image constant current source 7022, the output end of the mirror image constant current source 7022 is connected to the third analog-to-digital converter ADC3, and a resistor R33 is further connected between the output end of the mirror image constant current source 7022 and the ground. In this way, the voltage difference between the two ends of the detection resistor Rsensor is detected by the third comparator 7011, and amplified and outputted by the fourth switch tube Q4, and the mirror image constant current source 7022 is used to provide a bias current to the fourth switch tube Q4.

[0056] Please refer to Fig. 9 In some embodiments, a dynamic voltage regulation method for a DC regulated power supply circuit is provided, comprising the following steps: In the initialization state: Step 901: The controller MCU outputs a DC signal voltage V_out according to a set target, and controls the output of a second control signal Vctr2 to the voltage regulator module 102 through the second digital-to-analog converter DAC2. The voltage corresponding to the second control signal Vctr2 in the initial state is as follows: V ctr2 = V ref2 (1+R 23 / R 21 +R 23 / R 22 ) -V_out (R 23 / R 21 ); Among them, R 21 is the resistance value of resistor R21, R 22 is the resistance value of resistor R22, R 23 is the resistance value of resistor R23, V ctr2 is the voltage corresponding to the second control electrical signal, V_out is the preset target voltage value, V ref2 It is the reference voltage of the voltage regulator module.

[0057] Step 902: The controller MCU controls the output of the first control electrical signal Vctr1 to the switching power supply module 101 through the first digital-to-analog converter DAC1 according to the set target voltage V_mid. The voltage corresponding to the first control electrical signal Vctr1 in the initial state is expressed as follows: V ctr1 = V ref1 (1+R 13 / R 11 +R 13 / R 12 )- V_mid (R 13 / R 11 ); Among them, R 13 is the resistance value of resistor R13, R 11 is the resistance value of resistor R11, R 12 is the resistance value of resistor R12, V ctr1 is the voltage corresponding to the first control electrical signal, V_mid is the target voltage output by the switching power supply module 101, V ref1 It is the reference voltage of the switching power supply module.

[0058] In one embodiment, according to the definition of the dropout voltage in the above method (1), V dropout =V_mid-V_out-σ; Then, V_mid = V_out +V dropout +σ, then: V ctr1 = V ref1 (1+R 13 / R 11 +R 13 / R 12 )- (V_out +V dropout +σ) (R 13 / R 11 ); Among them, R 13 is the resistance value of resistor R13, R 11 is the resistance value of resistor R11, R 12 is the resistance value of resistor R12, V ctr1 is the voltage corresponding to the first control electrical signal, V_out is the preset target voltage value, V dropout is the leakage voltage, σ is the correction margin factor of the leakage voltage, V ref1 It is the reference voltage of the switching power supply module.

[0059] At this time, assuming the load current is I load, the power Ploss lost in the voltage regulator module 102 is: Ploss =Iload ×(V_mid - V_out); Since the energy conversion efficiency of the switching power supply module 101 is very high, the power Ploss lost in the voltage regulator module 102 is the main reason for the energy conversion efficiency loss of the entire DC voltage regulator circuit, and it is necessary to ensure that the voltage regulator module 102 works at a minimum V dropout Under certain voltage requirements, higher energy conversion efficiency can be achieved.

[0060] In another embodiment, according to the definition of the dropout voltage in method (2), V dropout =K × I load If according to Figure 8 The circuit of the load current detection module 104 shown in FIG. 1 calculates that V dropout = K × Vdet / (G × Rsensor), where Rsensor is the resistance of the sense resistor, Vdet is the voltage difference across the sense resistor, and G is the voltage gain factor.

[0061] It should be noted that the difference between this embodiment and the above embodiment is only that the calculation of the leakage voltage V dropout The methods are different, but other contents are the same and will not be repeated here.

[0062] After the above steps 902 and 903, the dynamic adjustment state is entered: Step 903: The controller MCU compares and calculates the actual third DC signal Vout obtained by the second analog-to-digital converter ADC2 and the voltage V_out corresponding to the target output DC signal to obtain ΔVout = V_out-Vout.

[0063] Step 904: the controller MCU adjusts the second control electrical signal Vctr2 in real time according to ΔVout, so that the third DC signal Vout approaches the voltage V_out corresponding to the target output DC signal, realizes closed-loop control, and obtains a third DC signal with high precision, low ripple and low noise.

[0064] Step 905: The controller MCU compares and calculates the actual second DC signal Vmid obtained by the first analog-to-digital converter ADC1 with the target voltage V_mid output by the switching power supply module 101 to obtain ΔVmid = V_mid– Vmid.

[0065] Step 906: The controller MCU adjusts the first control signal Vctr1 in real time according to ΔVmid, so that the second DC signal Vmid approaches the target voltage V_mid, and realizes closed-loop control.dropout When required, higher conversion efficiency and wide range output characteristics can be obtained.

[0066] Please refer to Fig.10 The embodiment of the present application also provides a measuring device, which can be but is not limited to an electronic measuring device such as an oscilloscope and a spectrum analyzer, and can include: a conversion circuit 1001, a DC regulated power supply circuit 1002, and one or more load circuits 1003, wherein the conversion circuit 1001 is used to perform DC conversion on an input AC signal and output a first DC signal; the DC regulated power supply circuit 1002 is used to perform voltage conversion processing on the first DC signal to output a third DC signal, and the third DC signal is used to provide a DC power supply signal to the load circuit 1003; the load circuit 1003 can be a clock circuit, a processing circuit, or other circuits in the measuring device.

[0067] This document is described with reference to various exemplary embodiments. However, those skilled in the art will recognize that changes and modifications may be made to the exemplary embodiments without departing from the scope of this document. For example, various operating steps and components for performing the operating steps may be implemented in different ways (e.g., one or more steps may be deleted, modified, or combined into other steps) depending on the specific application or considering any number of cost functions associated with the operation of the system.

[0068] In addition, as will be appreciated by those skilled in the art, the principles of this invention may be reflected in a computer program product on a computer-readable storage medium, which is pre-installed with a computer-readable program code. Any tangible, non-temporary computer-readable storage medium may be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-ROMs, DVDs, Blu Ray disks, etc.), flash memory, and / or the like. These computer program instructions may be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to form a machine, so that these instructions executed on a computer or other programmable data processing device may generate a device that implements a specified function. These computer program instructions may also be stored in a computer-readable memory, which may instruct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory may form a manufactured product, including an implementation device that implements a specified function. Computer program instructions may also be loaded onto a computer or other programmable data processing device, so that a series of operating steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device may provide steps for implementing a specified function.

[0069] Although the principles of this invention have been shown in various embodiments, many modifications of structures, arrangements, proportions, elements, materials and components particularly suitable for specific environments and operational requirements can be used without departing from the principles and scope of this invention. The above modifications and other changes or amendments will be included in the scope of this invention.

[0070] The foregoing specific description has been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of the present disclosure. Therefore, the consideration of the present disclosure will be illustrative rather than restrictive, and all these modifications will be included in its scope. Similarly, the advantages, other advantages and solutions to the problems of various embodiments have been described above. However, the benefits, advantages, solutions to the problems and any elements that can produce these, or make them more clear, should not be interpreted as critical, necessary or necessary. The term "include" and any other variants used in this article are all non-exclusive inclusions, so that the process, method, article or device including the list of elements not only includes these elements, but also includes other elements that are not explicitly listed or do not belong to the process, method, system, article or device. In addition, the term "coupled" and any other variants used in this article refer to physical connections, electrical connections, magnetic connections, optical connections, communication connections, functional connections and / or any other connections.

[0071] Those skilled in the art will appreciate that many changes may be made to the details of the above-described embodiments without departing from the basic principles of the invention. Accordingly, the scope of the invention should be determined from the following claims.

Claims

1. A DC regulated power supply circuit, characterized in that: include: A switching power supply module, comprising a first switching device; The switching power supply module is used to perform a first voltage conversion process on the input first DC power signal and output a required second DC power signal by turning on or off the first switching device; A voltage stabilizing module, comprising a second switching device; the voltage stabilizing module is used to perform a second voltage conversion process on the second DC power signal obtained from the switching power supply module based on the control electrode voltage of the second switching device, and output a required third DC power signal; a control and regulation module, connected to the switching power supply module to form a first control closed loop, for generating a first control electrical signal based on the second DC power signal, the third DC power signal and the leakage voltage of the second switching device, and controlling the first switching device in the switching power supply module to be turned on or off based on the first control electrical signal; The control and regulation module is connected to the voltage stabilizing module, and the switching power supply module, the voltage stabilizing module and the control and regulation module form a second control closed loop that is synchronously controlled with the first control closed loop; the control and regulation module is used to generate a second control electrical signal based on a voltage difference between the third DC signal and a preset target voltage value, and control the voltage stabilizing module to obtain a control electrode voltage of the second switching device based on the second control electrical signal, so as to perform a second voltage conversion process on the second DC signal to obtain a third DC signal that is close to the preset target voltage value; The first voltage conversion process is different from the second voltage conversion process, and the voltage difference between the second DC signal and the third DC signal fluctuates within a preset range of the leakage voltage of the second switching device.

2. The DC regulated power supply circuit according to claim 1, characterized in that: The control and regulation module includes: a controller, a first digital-to-analog converter, a first analog-to-digital converter, a second digital-to-analog converter, and a second analog-to-digital converter; The second analog-to-digital converter is connected to the output end of the voltage stabilizing module, and is used to convert the third DC signal into a third digital signal and output the third digital signal; The controller is connected to the second analog-to-digital converter, and is used to obtain the third digital signal, and determine the second control digital signal based on the voltage difference between the third digital signal and the preset target voltage value; The second digital-to-analog converter is connected to the controller and is used to convert the second control digital signal into a second control electrical signal; The first analog-to-digital converter is connected to the output end of the switching power supply module, and is used to convert the second DC signal into a second digital signal and output the second digital signal; The controller is connected to the first analog-to-digital converter, and is used to obtain the second digital signal, and determine a first control digital signal based on the second digital signal, the third digital signal and the dropout voltage of the second switch device; The first digital-to-analog converter is connected to the controller, and is used for converting the first control digital signal into a first control electrical signal.

3. The DC regulated power supply circuit according to claim 2, characterized in that: Also includes: The control and regulation module is used to determine the leakage voltage of the second switch device according to the target output voltage of the switch power supply module and the preset target voltage value; or, The control and regulation module is used to obtain the load current of the DC regulated power supply circuit, and determine the leakage voltage of the second switch device according to the load current and a preset proportional factor.

4. The DC regulated power supply circuit according to claim 3, characterized in that: Also includes: The load current detection module is connected to the output end of the voltage stabilizing module and is used to detect the current at the output end of the voltage stabilizing module to obtain the load current of the DC regulated power supply circuit.

5. The DC regulated power supply circuit according to claim 4, characterized in that: The load current detection module comprises: A detection resistor, one end of which is connected to the output end of the voltage stabilizing module, and the other end of which is used to output the load current; A voltage difference detection unit, having a first input end and a second input end, wherein the first input end is connected to one end of the detection resistor, and the second input end is connected to the other end of the detection resistor, and the voltage difference amplification unit is used to obtain the voltage difference between the two ends of the detection resistor and output a voltage difference signal; the voltage difference signal is used to characterize the magnitude of the load current; A third analog-to-digital converter is connected to the output end of the voltage difference detection unit, and is used for converting the voltage difference signal into a digital voltage difference signal, and outputting the digital voltage difference signal to the controller.

6. The DC regulated power supply circuit according to claim 5, characterized in that: The voltage difference detection unit is also used to amplify the acquired voltage difference signal across the detection resistor.

7. The DC regulated power supply circuit according to claim 2, characterized in that: Also includes: A first signal processing module; The first signal processing module includes: a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C11, a capacitor C12, a capacitor C13 and an inductor L11; One end of the resistor R13 is connected to the output end of the first digital-to-analog converter, the other end of the resistor R13 is connected to one end of the resistor R11 and one end of the resistor R12, the other end of the resistor R11 is connected to the output end of the switching power module, one end of the capacitor C11 is connected to the input end of the switching power module, the other end of the capacitor C11 is connected to the ground, the end of the resistor R13 connected to the resistor R11 and the resistor R12 is used to output the first control electrical signal to the feedback end of the switching power module, and the other end of the resistor R12 is grounded; One end of the resistor R14 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the ground, the other end of the resistor R14 is connected to one end of the capacitor C13, and the other end of the capacitor C13 is connected to the ground, wherein the end of the resistor R14 connected to the resistor R15 is used to connect to the input end of the first analog-to-digital converter, and the end of the resistor R14 connected to the capacitor C13 is used to connect to the output end of the switching power supply module; One end of the inductor L11 is connected to the output end of the switching power supply module, the other end of the inductor L11 is connected to one end of the capacitor C12, the other end of the capacitor C12 is connected to the ground, and the end of the inductor L11 connected to the capacitor C12 is used to output a second DC signal.

8. The DC regulated power supply circuit according to claim 7, characterized in that: Also includes: A second signal processing module; The second signal processing module includes: a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a capacitor C21, a capacitor C22 and a capacitor C23; One end of the resistor R23 is connected to the output end of the second digital-to-analog converter, the other end of the resistor R23 is connected to one end of the resistor R21 and one end of the resistor R22, the other end of the resistor R21 is connected to the output end of the voltage stabilizing module, one end of the capacitor C21 is connected to the input end of the voltage stabilizing module, the other end of the capacitor C21 is connected to the ground, the end of the resistor R23 connected to the resistor R21 and the resistor R22 is used to output the second control electrical signal to the feedback end of the voltage stabilizing module, and the other end of the resistor R22 is grounded; One end of the resistor R24 ​​is connected to one end of the resistor R25, the other end of the resistor R25 is connected to the ground, the other end of the resistor R24 ​​is connected to one end of the capacitor C23, and the other end of the capacitor C23 is connected to the ground, wherein the end of the resistor R24 ​​connected to the resistor R25 is used to connect to the input end of the second analog-to-digital converter, and the end of the resistor R24 ​​connected to the capacitor C23 is used to connect to the output end of the voltage stabilizing module; One end of the capacitor C22 is connected to the output end of the voltage stabilizing module, and the other end of the capacitor C22 is connected to the ground.

9. The DC regulated power supply circuit according to claim 8, characterized in that: The DC regulated power supply circuit has at least an initial state; wherein, In the initial state: The second control electrical signal is determined according to the following expression: V ctr2 = V ref2 (1+R 23 / R 21 +R 23 / R 22 ) -V_out (R 23 / R 21 ); Among them, R 21 is the resistance value of resistor R21, R 22 is the resistance value of resistor R22, R 23 is the resistance value of resistor R23, V ctr2 is the voltage corresponding to the second control electrical signal, V_out is the preset target voltage value, V ref2 It is the reference voltage of the voltage regulator module; The first control electrical signal is determined according to the following expression: V ctr1 = V ref1 (1+R 13 / R 11 +R 13 / R 12 )- (V_out +V dropout +σ) (R 13 / R 11 ); Among them, R 13 is the resistance value of resistor R13, R 11 is the resistance value of resistor R11, R 12 is the resistance value of resistor R12, V ctr1 is the voltage corresponding to the first control electrical signal, V_out is the preset target voltage value, V dropout is the leakage voltage, σ is the correction margin factor of the leakage voltage, V ref1 It is the reference voltage of the switching power supply module.

10. The DC regulated power supply circuit according to any one of claims 2 to 9, characterized in that: Also includes: A serial interface bus is used for communication between the controller and the first digital-to-analog converter, the first analog-to-digital converter, the second digital-to-analog converter, and the second analog-to-digital converter.

11. A measuring device, characterized in that: include: A conversion circuit, used for performing DC conversion on an input AC signal and outputting a first DC signal; A DC regulated power supply circuit, wherein the DC regulated power supply circuit is a circuit as claimed in any one of claims 1 to 10, and is used for performing voltage conversion processing on the first DC signal to output a third DC signal; One or more load circuits, the third DC power signal is used to provide a DC power signal to the load circuit.

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