Ultra-low voltage stabilizing circuit and method, and control module

Abstract

The present application relates to the technical field of voltage stabilizing circuits, and in particular to an ultra-low voltage stabilizing circuit, method, and control module. The ultra-low voltage stabilizing circuit includes: a voltage output node, which is used to output a first voltage; a control module, which controls the first voltage based on a user's operation instruction, and the operation instruction carries a target value of the first voltage; a voltage stabilizing module, which is used to discharge the leakage voltage acting on the voltage output node, and includes a first discharge resistor and a switching transistor, the first discharge resistor and the switching transistor are connected in series between the voltage output node and the ground potential; wherein the control module is configured to control the switching transistor to turn on in response to the target value being less than a set threshold, and to control the switching transistor to turn off in response to the target value being greater than the set threshold.

Description

Technical Field

[0001] The present application relates to the technical field of voltage stabilizing circuits, and in particular to an ultra-low voltage stabilizing circuit and method, and a control module. Background Art

[0002] In the prior art, a low dropout regulator (LDO) or a switching power supply is generally used to achieve low voltage output. However, in this traditional method, due to the inherent existence of leakage voltage, the voltage stability is poor when the low voltage is output. In particular, it is difficult for this traditional method to stably output an ultra-low voltage below 50mV. Summary of the invention

[0003] In view of this, the present application proposes an ultra-low voltage stabilization circuit and method, and a control module.

[0004] In a first aspect, the present application proposes an ultra-low voltage stabilizing circuit, comprising:

[0005] A voltage output node, used to output a first voltage;

[0006] a control module, configured to control the first voltage based on an operation instruction of a user, wherein the operation instruction carries a target value of the first voltage;

[0007] a voltage stabilizing module, which is used to discharge the leakage voltage acting on the voltage output node, and comprises a first discharge resistor and a switch transistor, wherein the first discharge resistor and the switch transistor are connected in series between the voltage output node and the ground potential;

[0008] The control module is configured to control the switch transistor to be turned on in response to the target value being less than a set threshold, and to control the switch transistor to be turned off in response to the target value being greater than the set threshold.

[0009] In some possible implementations, the control module is configured to control the switch transistor to be turned on in a pulsed manner in response to the target value being less than a set threshold.

[0010] In some possible implementations, the following further includes:

[0011] A voltage acquisition module, whose input end is connected to the voltage output node and whose output end is connected to the control module, so as to transmit an acquisition voltage to the control module, wherein the acquisition voltage is positively correlated with the voltage at the input end of the voltage acquisition module;

[0012] The controlling the first voltage based on the user's operation instruction specifically includes:

[0013] Providing a control voltage based on an operation instruction of a user, and controlling the first voltage by causing the control voltage to act on the circuit;

[0014] Wherein, the control module is further configured to adjust the control voltage based on the collected voltage.

[0015] In some possible implementations, the voltage stabilizing module includes a first op amp, the first op amp having a first negative input terminal connected to the voltage acquisition module, a first positive input terminal connected to the control module, and a first output terminal connected to the gate of the switching transistor, wherein the first output terminal is configured to: output a first high level signal in response to a voltage at the first positive input terminal being higher than a voltage at the first negative input terminal, and output a first low level signal in response to a voltage at the first positive input terminal being lower than a voltage at the first negative input terminal;

[0016] The switch transistor is configured to be turned on in response to the first high level signal and turned off in response to the first low level signal;

[0017] The control module is configured to: in response to the target value being less than the set threshold, provide a trigger voltage to the first positive input terminal to turn on the switching transistor; in response to the target value being greater than the set threshold, not provide a trigger voltage to the first positive input terminal to turn off the switching transistor.

[0018] In some possible implementations, the control module is configured to provide the trigger voltage to the first positive input terminal in a pulsed manner in response to the target value being less than the set threshold value, so as to turn on the switch transistor in a pulsed manner.

[0019] In some possible implementations, the voltage stabilizing module further includes a second bleeder resistor connected in series between the voltage output node and the ground potential, and a resistance value of the second bleeder resistor is greater than that of the first bleeder resistor.

[0020] In some possible implementations, the following further includes:

[0021] A voltage source configured to output an initial voltage with an adjustable magnitude based on the control of the control module;

[0022] a step-down module, comprising an input terminal connected to the output terminal of the voltage source and an output terminal connected to the voltage output node at the same potential, and configured to step down the initial voltage based on the control of the control module, so as to output the first voltage smaller than the initial voltage from the output terminal of the step-down module;

[0023] a voltage regulating module, comprising a second op amp, a first resistor, a second resistor and a third resistor, wherein the first resistor and the second resistor are connected in series between the output terminal of the step-down module and the ground potential, one end of the third resistor is connected between the first resistor and the second resistor, and the other end is connected to the control module to obtain the control voltage from the control module, the second op amp has a second positive input terminal for receiving a reference voltage, a second negative input terminal connected between the first resistor and the second resistor, and a second output terminal connected to the control module, and the second output terminal is configured to output a second high level signal in response to a voltage of the second positive input terminal being higher than a voltage of the second negative input terminal, and output a second low level signal in response to a voltage of the second positive input terminal being lower than a voltage of the second negative input terminal;

[0024] Wherein, the control module is configured as follows:

[0025] In response to the second high level signal, controlling the voltage source to increase the initial voltage, and / or controlling the voltage reduction module to reduce the voltage reduction amplitude of the initial voltage;

[0026] In response to the second low level signal, the voltage source is controlled to lower the initial voltage, and / or the voltage reduction module is controlled to increase the voltage reduction amplitude of the initial voltage.

[0027] In some possible implementations, the buck module includes a switch device, a capacitor, an inductor and a freewheeling diode;

[0028] The switch device and the inductor are connected in series between the input terminal and the output terminal of the buck module, and the control module is connected to the control terminal of the switch device to control the conduction frequency and duty cycle of the switch device;

[0029] The freewheeling diode is connected between the upstream end of the inductor and the ground potential, and the anode of the freewheeling diode faces the ground potential;

[0030] The capacitor is connected between the downstream end of the inductor and the ground potential;

[0031] The voltage acquisition module comprises a fourth resistor and a fifth resistor connected in series between the voltage output node and the ground potential, and the output end of the voltage acquisition module is led out from between the fourth resistor and the fifth resistor.

[0032] In a second aspect, a method for ultra-low voltage stabilization is proposed, which is applied to the circuit as described in the first aspect, and the method comprises:

[0033] The control module receives the operation instruction of the user;

[0034] If the target value is less than the set threshold, the control module provides a trigger voltage to the first positive input terminal to turn on the switch transistor;

[0035] If the target value is greater than the set threshold, the control module does not provide a trigger voltage to the first positive input terminal to keep the switch transistor turned off;

[0036] The control module determines a control voltage based on the target value;

[0037] The control module provides the control voltage to the third resistor.

[0038] In a third aspect, a control module is proposed, comprising a memory and a processor, wherein a computer program is stored in the memory, and when the computer program runs on the processor, the control module executes the method described in the second aspect.

[0039] According to the ultra-low voltage stabilizing circuit provided in the present application, when the circuit operates in a mode of outputting an ultra-low voltage, the leakage voltage acting on the voltage output node can be automatically and quickly discharged, thereby ensuring the temperature stability of the ultra-low voltage output on the voltage output node. In addition, when the circuit operates in a non-ultra-low voltage mode, the corresponding discharge path can be automatically disconnected, thereby avoiding burning of related devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present application, rather than limiting the present application.

[0041] Figure 1 1 is a schematic diagram of the structure of an ultra-low voltage stabilizing circuit provided in one embodiment of the present application. The dashed boxes without figure marks in the figure represent other parts of the circuit other than the illustrated part.

[0042] Figure 2 1 is a schematic diagram of the structure of an ultra-low voltage stabilizing circuit provided in one embodiment of the present application. The dashed boxes without figure marks in the figure represent other parts of the circuit other than the illustrated part.

[0043] Figure 3 It is a structural schematic diagram of an ultra-low voltage stabilizing circuit provided in one embodiment of the present application.

[0044] Figure 4 It is a flow chart of a method for ultra-low voltage stabilization provided in one embodiment of the present application.

[0045] Figure 5 It is a flow chart of a method for ultra-low voltage stabilization provided in one embodiment of the present application.

[0046] Description of reference numerals:

[0047] 10-voltage output node, 20-voltage stabilizing module, 30-voltage acquisition module, 40-voltage regulating module, 50-voltage step-down module;

[0048] R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, R6-first discharge resistor, R7-second discharge resistor;

[0049] U1B-first op amp, P1-first positive input terminal, P2-first negative input terminal, P3-first output terminal;

[0050] U2B-second op amp, P4-second positive input terminal, P5-second negative input terminal, P6-second output terminal;

[0051] Q1 - switching transistor;

[0052] S1-switching device, D1-freewheeling diode; L1-inductor, C1-capacitor;

[0053] VOUT-first voltage, VIN-initial voltage, VMCU-control voltage, Vm-collection voltage, Vt-trigger voltage. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the embodiment of the present application will be clearly and completely described below in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application. It can be understood that, in the absence of conflict, some technical means of the various embodiments described herein can be replaced or combined with each other.

[0055] In the description of this application, if there are terms such as "first", "second", etc., they are only used to distinguish the objects described and do not have any order or technical meaning. Therefore, an object defined as "first", "second", etc. may explicitly or implicitly include one or more of the objects. In addition, "one" or "a" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one, and "multiple" means no less than two.

[0056] In the description of this specification, reference to "one embodiment" or "some embodiments" etc. means that one or more embodiments of the present application include a particular feature, structure or characteristic described in conjunction with the embodiment. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0057] Figures 1 to 3 The ultra-low voltage stabilizing circuit (hereinafter, sometimes referred to as the circuit) provided by some embodiments of the present application is shown. The circuit can output an ultra-low voltage below 50mV, and can also output a relatively high voltage above 50mV, such as 2V or 3V. Figures 1 to 3 In the various drawings of the present invention, the same or similar components are given the same or similar reference numerals, and repeated detailed description of the same parts is omitted.

[0058] First, see Figure 1 ,exist Figure 1 In the illustrated embodiment, the circuit includes a voltage output node 10 , a control module and a voltage stabilization module 20 .

[0059] The voltage output node 10 is used to output a first voltage VOUT. The first voltage VOUT may be as low as 50 mV or less (an ultra-low voltage close to 0 V).

[0060] The control module can control the aforementioned first voltage VOUT based on the user's operation instruction, wherein the operation instruction carries the target value of the first voltage VOUT. Exemplarily, the user (e.g., the operator of the semiconductor testing equipment) can input the target value of the first voltage VOUT that the voltage output node 10 of the circuit expects to output, such as 40mV or 2V, by means of a mouse and a keyboard coupled to the control module. When the control module receives the user's operation instruction, the circuit can be configured according to the target value so that the voltage output node 10 outputs the first voltage VOUT at the target value.

[0061] In actual applications, there may be leakage voltage in the circuit. If the leakage voltage acts on the voltage output node 10, it will cause the actual voltage on the voltage output node 10 to deviate from the required first voltage VOUT. In particular, when the first voltage VOUT is an extremely low voltage below 50mV, the aforementioned voltage deviation problem will be particularly significant. For example, in an application example where the circuit is applied to a semiconductor test device, based on the control of the control module, the circuit intends to continuously and stably output a 40mV first voltage VOUT to the semiconductor device under test through its voltage output node 10. However, at a certain time, because there is a leakage voltage applied to the voltage output node 10, the actual voltage of the voltage output node 10 at that time is as high as 1.8V. Then the aforementioned semiconductor device under test may be burned because the actual voltage it receives is much greater than the rated voltage required for its normal operation.

[0062] Advantageously, the aforementioned voltage stabilizing module 20 configured in the circuit can discharge the leakage voltage acting on the voltage output node 10, thereby avoiding the above-mentioned problem.

[0063] Specifically, the voltage stabilizing module 20 includes a first bleeder resistor R6 and a switch transistor Q1, which are connected in series between the voltage output node 10 and the ground potential. The control module is configured to: in response to the aforementioned target value being less than a set threshold, control the switch transistor Q1 to be turned on; in response to the target value being greater than the set threshold, control the switch transistor Q1 to be turned off.

[0064] In some embodiments, the aforementioned set threshold is 50mV. Thus, when the target value set by the user is less than the set threshold, it indicates that the circuit is currently operating in an ultra-low voltage mode, and therefore, the drain voltage acting on the voltage output node 10 is likely to far exceed (in terms of numerical multiples) the current first voltage VOUT, thereby causing the actual output voltage of the voltage output node 10 to seriously deviate from the desired target value, which is likely to cause an electrical fault in the power-consuming object (e.g., the aforementioned semiconductor device under test) supplied with power by the voltage output node 10. Fortunately, when the target value is less than the set threshold, the control module will automatically control the switch transistor Q1 to turn on, so that the drain voltage acting on the voltage output node 10 is discharged to the ground terminal in a current manner via the first discharge resistor R6, and thereby the first voltage VOUT output by the voltage output node 10 becomes a stable target value voltage, such as 40mV.

[0065] In some cases, a circuit failure may occur, resulting in the following situation: even if the control module configures the circuit according to the target value of the first voltage VOUT in the control instruction, the first voltage VOUT provided by the voltage output node 10 is significantly higher than the target value due to a hardware failure. If the control module controls the switch transistor Q1 to be continuously turned on for a long time in this case, the high fault voltage continuously provided on the voltage output node 10 will continue to act on the discharge path formed by the first discharge resistor R6 and the switch transistor Q1, causing a large current to flow through the first discharge resistor R6 for a long time, thereby causing the first discharge resistor R6 to heat up violently or even burn (or causing nearby devices to burn). For this reason, in order to reduce the possibility of related devices being burned, in some embodiments, the control module is more specifically configured to control the switch transistor Q1 to be turned on in a pulsed manner (rather than being turned on continuously for a long time) in response to the target value being greater than the set threshold. For example, when the target value is greater than the set threshold, the control module controls the switch transistor Q1 to be turned on for a short time and then turned off immediately. After a certain period of time, the switch transistor Q1 is controlled to be turned on for a short time and then turned off immediately, and the switch transistor Q1 is turned on and off periodically at the set frequency. In addition, it should be understood that, under normal circumstances, even if the switch transistor Q1 is turned on for a very short time, it is sufficient to discharge the leakage voltage on the circuit.

[0066] In addition, the voltage stabilizing module 20 also includes a second discharge resistor R7 connected in series between the voltage output node 10 and the ground potential, and the resistance of the second discharge resistor R7 is much greater than the resistance of the first discharge resistor R6. For example, the resistance of the second discharge resistor R7 can be hundreds of times that of the first discharge resistor R6. Therefore, the voltage stabilizing module 20 has two discharge paths for discharging the leakage voltage, one of which (the first discharge path) passes through the first discharge resistor R6, and the other discharge path (the second discharge path) passes through the second discharge resistor R7. Since the resistance of the first discharge resistor R6 is smaller than that of the second discharge resistor R7, the discharge speed of the first discharge path is faster than that of the second discharge path, but under the same leakage voltage, the first discharge resistor R6 is more likely to heat up than the second discharge resistor R7.

[0067] The control module may be an MCU (Microcontroller Unit).

[0068] See also Figure 2 ,exist Figure 2In the illustrated embodiment, the circuit may further include a voltage acquisition module 30, the input end of the voltage acquisition module 30 is connected to the voltage output node 10, and the output end of the voltage acquisition module 30 is connected to the control module to transmit a collection voltage Vm to the control module, and the collection voltage Vm is positively correlated with the voltage at the input end of the voltage acquisition module 30. Obviously, the value of the collection voltage Vm can reflect the voltage value at the input end of the voltage acquisition module 30 (which is also the voltage value of the voltage output node 10).

[0069] Furthermore, the control module controls the first voltage VOUT based on the user's operation instruction, which may specifically include: the control module provides a control voltage VMCU based on the user's operation instruction, and controls the first voltage VOUT by causing the control voltage VMCU to act on the circuit. In addition, the control module is further configured to adjust the control voltage VMCU based on the collected voltage Vm.

[0070] In this way, the control module can determine the actual voltage of the current voltage output node 10 according to the collected voltage Vm provided by the voltage collection module 30. When the actual voltage is inconsistent with the ideal first voltage VOUT, that is, the target value (this situation may occur due to the influence of other factors such as line internal resistance), the control module will adjust the size of the control voltage VMCU accordingly. For example, when the actual voltage value of the voltage output node 10 is too large, the control module increases the control voltage VMCU. When the actual voltage value of the voltage output node 10 is too small, the control module reduces the control voltage VMCU until the actual voltage value is adjusted to be consistent with the target value (within the allowable error range).

[0071] The voltage acquisition module 30 includes a fourth resistor R4 and a fifth resistor R5 connected in series between the voltage output node 10 and the ground potential, and the output end of the voltage acquisition module 30 is led out from between the fourth resistor R4 and the fifth resistor R5. In this embodiment, the fourth resistor R4 and the fifth resistor R5 form a voltage divider circuit, and the fifth resistor R5 can be a resistor with a higher resistance than the aforementioned second discharge resistor R7.

[0072] like Figure 2 As shown, the voltage stabilizing module 20 may include a first op amp U1B, which has a first negative input terminal P2 connected to the voltage acquisition module 30, a first positive input terminal P1 connected to the control module, and a first output terminal P3 connected to the gate of the switching transistor Q1. The first output terminal P3 is configured to output a first high level signal in response to the voltage of the first positive input terminal P1 being higher than the voltage of the first negative input terminal P2, and to output a low level signal in response to the voltage of the first positive input terminal P1 being lower than the voltage of the first negative input terminal P2.

[0073] Furthermore, the switch transistor Q1 is configured to be turned on in response to the aforementioned first high-level signal, and to be turned off in response to the aforementioned first low-level signal. In addition, the control module is configured to: in response to the target value being less than the set threshold, provide a trigger voltage Vt to the first positive input terminal P1, thereby turning on the switch transistor Q1; in response to the target value being greater than the set threshold, not provide the trigger voltage Vt to the first positive input terminal P1, thereby turning off the switch transistor Q1.

[0074] More specifically, the control module may be configured to: in response to the target value being less than a set threshold, provide a trigger voltage Vt to the first positive input terminal P1 in a pulsed manner, thereby turning on the switch transistor Q1 in a pulsed manner.

[0075] The trigger voltage Vt provided by the control module may correspond to the normal drain voltage of the voltage output node 10 when it is operating in the ultra-low voltage mode. For example, if the normal drain voltage during ultra-low voltage output is 1.5V, then the trigger voltage Vt may be set to 1.5V, and the resistance of the first discharge resistor R6 may be configured such that it will not generate intense heat when discharging the 1.5V drain voltage, and the resistance may not be too large to affect the discharge speed of the drain voltage. Such a design has at least the following advantages:

[0076] 1. In the ultra-low voltage output mode, if the drain voltage accidentally exceeds 1.5V and reaches 2.5V, the first output terminal P3 of the first comparator will output a low-level signal because the voltage of its first positive input terminal P1 is lower than the voltage of its first negative input terminal P2, thereby keeping the switch transistor in the off state. Therefore, a large current will not flow through the low-resistance first voltage bleeder resistor and generate intense heat, thereby preventing related devices from being burned. In addition, the drain voltage that is accidentally as high as 2.5V will be discharged relatively slowly through the high-resistance second bleeder resistor R7 until the drain voltage is discharged to 1.5V, and the switch transistor will be turned on immediately (such as, turned on in a pulse manner) to quickly discharge the remaining drain voltage.

[0077] 2. In the ultra-low voltage output mode, if the circuit has the aforementioned fault and causes the first voltage VOUT actually provided by the voltage output node 10 to be significantly higher than the target value below 50mV, for example, the actual value of the first voltage VOUT reaches 3V, then the first output terminal P3 of the first comparator will output a low-level signal because the voltage of its first positive input terminal P1 is lower than the voltage of its first negative input terminal P2, thereby keeping the switching tube transistor in the off state. Therefore, the low-resistance first voltage bleeder resistor will not have a large current flowing through it and generate intense heat, thereby preventing related devices from being burned out.

[0078] See also Figure 3 ,exist Figure 3In the illustrated embodiment, the circuit further includes a voltage source, a voltage reduction module 50 and a voltage regulation module 40 .

[0079] The voltage source is configured to output an initial voltage VIN with an adjustable magnitude based on the control of the control module.

[0080] The buck module 50 has an input terminal connected to the output terminal of the voltage source and an output terminal connected to the voltage output node 10 at the same potential, so in a sense, the voltage output node 10 can also be regarded as the output terminal of the buck module 50. In addition, the buck module 50 is configured to step down the initial voltage VIN provided by the voltage source based on the control of the control module, so as to output the first voltage VOUT smaller than the initial voltage VIN from the output terminal of the buck module 50.

[0081] In detail, the buck module 50 includes a switch device S1, a freewheeling diode D1, a capacitor C1 and an inductor L1. The switch device S1 and the inductor L1 are connected in series between the input end and the output end of the buck module 50, and the control module is connected to the control end of the switch device S1 to control the conduction frequency and duty cycle of the switch device S1. The freewheeling diode D1 is connected between the upstream end of the inductor L1 and the ground potential, and the positive pole of the freewheeling diode D1 faces the ground potential. The capacitor C1 is connected between the downstream end of the inductor L1 and the ground potential. In addition, the switch device S1 can be a transistor.

[0082] For the step-down module 50, the relationship between its input voltage and its output voltage is:

[0083] VOUT=VIN*D (1)

[0084] In formula (1), VIN is the input voltage of the buck module 50, which is equal to the aforementioned initial voltage provided by the voltage source; VOUT is the output voltage of the buck module 50, which is equal to the first voltage of the voltage output node 10; and D is the duty cycle of the switch device.

[0085] It can be seen from formula (1) that by controlling the size of VIN and the size of D, the size of the output voltage VOUT, that is, the size of the first voltage, can be controlled.

[0086] D = TON / T (2)

[0087] T = 1 / F (3)

[0088] Wherein, T is the switching cycle of the switching device S1, TON is the conduction time of the switching device S1 in one cycle, and F is the conduction frequency (or switching frequency) of the switching device S1.

[0089] From equations (2) and (3), we can get D = TON * F;

[0090] Combining with formula (1), we can get:

[0091] VOUT=VIN*TON*F (4)

[0092] From formula (4), it can be seen that if VOUT is expected to be within 50mV, at least one of VIN, TON, and F needs to be close to 0. However, VIN is provided by a voltage source and has a minimum voltage limit, such as a minimum of 3V. Its size is generally determined based on the minimum operating voltage of the components in the circuit. F is the switching frequency of the switching device S1, and it cannot be close to 0, otherwise, the inductor L1 will operate abnormally. Since both VIN and F cannot be too small, it can be concluded from formula (4) that only by making D close to 0 and VIN and F as small as possible can VOUT be close to 0V (for example, 40mV) output.

[0093] TON has a minimum value limit and cannot be infinitely small because the switch device S1 has a minimum rise conduction time. The inductor L1 also has a minimum operating frequency limit. Therefore, the best way to get VOUT close to 0 is to make VIN, TON and F reach their respective minimum values ​​as much as possible. In particular, parameter F should be slightly larger to suppress the ripple of the first voltage VOUT. The specific value of F can be determined based on the size of the ripple voltage detected by the control module.

[0094] In addition, it can be understood that when VIN, TON and F are all set to the maximum values ​​that can be achieved, the first voltage VOUT reaches the maximum value, and thus the voltage output node 10 of the circuit can also output a larger first voltage VOUT.

[0095] The control module can adjust TON and F by applying a control signal to the control terminal of the switch tube device, and the control module can adjust VIN by applying a control signal to the voltage source. Before adjustment, the rise time tr and the turn-on time td(on) of the switch device S1 need to be determined. When an ultra-low voltage output close to 0V is required, the minimum TON time can be r+td(on).

[0096] In order to facilitate readers to understand the present technology, the following examples are given (the following calculated values ​​and example values ​​may be approximate values):

[0097] Exemplarily, the input voltage VIN=3V-12V, the desired output voltage VOUT=50mV=0.05V, tr=10nS, td(on)=8nS.

[0098] According to VIN*D=VOUT, the value VIN=3V, 3*D=0.05, D=0.05 / 3=0.0167.

[0099] D=TON*F=0.0167, TON=tr+td(on)=10+8=18nS.

[0100] Considering the effect of frequency on the magnetic core, we can take TON=300nS=0.3uS, then:

[0101] F=0.0167 / 0.3=55KHz (5)

[0102] Calculation: VIN*TON*F=3*0.3*55 / 1000=0.0495V=50mV.

[0103] It can be seen from formula (5) that the control module can also appropriately adjust the length of the TON time according to the size of F, so that the efficiency of the entire circuit system is the highest and the heat generation is lower.

[0104] In addition, you can also take TON=3uS, so F=5.5K, and make the selection based on ripple and efficiency. If you find that the ripple voltage is too large, you can increase F and reduce TON and VIN. When the control module adjusts these parameters, the change rate each time can be controlled within 20% of the current parameters, and the theoretical rated values ​​are compared in turn, and the cycle is adjusted and dynamically adjusted until the required efficiency, ripple and voltage are met.

[0105] The voltage regulating module 40 includes a second amplifier U2B, a first resistor R1, a second resistor R2 and a third resistor R3. The first resistor R1 and the second resistor R2 are connected in series between the output terminal of the step-down module 50 and the ground potential, that is, connected in series between the voltage output node 10 and the ground potential. One end of the third resistor R3 is connected between the first resistor R1 and the second resistor R2, and the other end is connected to the control module to obtain the aforementioned control voltage VMCU from the control module. The second amplifier U2B has a second positive input terminal P4 for receiving a reference voltage, a second negative input terminal P5 connected between the first resistor R1 and the second resistor R2, and a second output terminal P6 connected to the control module, and the reference voltage can be provided by the control module, and the size of the reference voltage is controlled by the control module. In addition, the second output terminal P6 of the second amplifier U2B is configured to: output a second high level signal in response to the voltage of the second positive input terminal P4 being higher than the voltage of the second negative input terminal P5, and output a second low level signal in response to the voltage of the second positive input terminal P4 being lower than the voltage of the second negative input terminal P5.

[0106] In addition, the control module is further configured to:

[0107] In response to the aforementioned second high level signal, the voltage source VMCU is controlled to increase the initial voltage VIN, and / or the voltage reduction module 50 is controlled to reduce the voltage reduction amplitude of the initial voltage VIN;

[0108] In response to the second low level signal, the voltage source VMCU is controlled to lower the initial voltage VIN, and / or the voltage reduction module 50 is controlled to increase the voltage reduction amplitude of the initial voltage VIN.

[0109] Exemplarily, under the action of the second high-level signal, the control module controls the voltage VMCU source to increase the initial voltage VIN, and controls the buck module 50 to reduce the voltage reduction amplitude of the initial voltage VIN; under the action of the second high-low level signal, the control module controls the voltage VMCU source to lower the initial voltage VIN, and controls the buck module 50 to increase the voltage reduction amplitude of the initial voltage VIN.

[0110] In this way, when the resistance values ​​of the first resistor R1, the second resistor R2 and the third resistor R3 are fixed, the control module can change the magnitude of the first voltage VOUT on the voltage output node 10 based on the adjustment of the control voltage VMCU and the reference voltage. When the control voltage VMCU and the reference voltage are set to corresponding values, the high level signal or low level signal output by the second operational amplifier will continuously act on the control module, so that the control module controls the voltage VMCU source and / or the step-down module 50 to perform corresponding processing, so that the voltage on the voltage output node 10 reaches the target value given by the user.

[0111] In detail, according to the KCL law (Kirchhoff's current law), the following relationship can be obtained:

[0112] (6)

[0113] According to the relationship (6), the control module can achieve the change of the first voltage VOUT by adjusting the value of the reference voltage or the control voltage VMCUVMCU. When the control voltage VMCU remains unchanged and the reference voltage is lowered, the first voltage VOUT follows and is positively correlated with the reference voltage; when the reference voltage remains unchanged and the control voltage VMCU is increased, the first voltage VOUT becomes lower and is negatively correlated with the control voltage VMCU.

[0114] Based on the above discussion, it can be known that, on the one hand, the control module can obtain the desired first voltage VOUT by adjusting the control voltage VMCU, that is, the control module can control the first voltage VOUT by providing the control voltage VMCU; on the other hand, the control module can also obtain the desired first voltage VOUT by adjusting the reference voltage, that is, the control module can also control the first voltage VOUT by providing the reference voltage.

[0115] In some embodiments, the reference voltage is preset and fixed, and the control module automatically adjusts the control voltage VMCU according to the target value of the first voltage VOUT set by the user, but does not automatically adjust the value of the reference voltage. If the reference voltage is desired to be changed, the user needs to input an operation instruction to adjust the reference voltage to the control module separately.

[0116] In some other embodiments, the control module automatically adjusts the magnitude of the control voltage VMCU based on a target value of the first voltage VOUT set by a user, and also automatically adjusts the magnitude of the reference voltage based on the target value.

[0117] In some other embodiments, the control voltage VMCU is preset and fixed, and the control module automatically adjusts only the reference voltage according to the target value of the first voltage VOUT set by the user, but does not automatically adjust the value of the control voltage VMCU. If the control voltage VMCU is desired to be changed, the user needs to input an operation instruction to adjust the control voltage VMCU to the control module separately.

[0118] Based on the above description, see Figure 4 The present application also provides a method for stabilizing ultra-low voltage, which can be applied to Figures 1 to 3 Any of the extra-low voltage stabilizing circuits shown, comprising:

[0119] S401, a control module receives an operation instruction from a user, where the operation instruction carries a target value of a first voltage VOUT.

[0120] Exemplarily, a user (e.g., an operator of semiconductor testing equipment) can use a keyboard coupled to the control module to input the first voltage VOUT that he or she expects the voltage output node 10 of the circuit to output, such as 40mV or 2V, and press a confirmation key to complete the issuance of the operation instruction.

[0121] S402, if the target value is less than the set threshold, the control module provides a trigger voltage Vt to the first positive input terminal P1 of the first operational amplifier U1B to turn on the switch transistor Q1.

[0122] S403, if the target value is greater than the set threshold, the control module does not provide the trigger voltage Vt to the first positive input terminal P1, so that the switch transistor Q1 remains disconnected.

[0123] S404: The control module determines a control voltage VMCU based on the target value.

[0124] When the user issues the aforementioned operation instruction carrying the target value of the first voltage VOUT, the control module can determine the required control voltage VMCU based on the aforementioned relationship (6), and the reference voltage in the relationship (6) can be a preset known value.

[0125] S205, the control module provides a control voltage VMCU to the third resistor R3.

[0126] Based on the above description, please see Figure 5 The present application also provides a method for stabilizing ultra-low voltage, which is also applied to Figures 1 to 3 Any of the extra-low voltage stabilizing circuits shown, comprising:

[0127] S501, a control module receives an operation instruction from a user, where the operation instruction carries a target value of a first voltage VOUT.

[0128] Exemplarily, a user (e.g., an operator of semiconductor testing equipment) can use a keyboard coupled to the control module to input the first voltage VOUT that he or she expects the voltage output node 10 of the circuit to output, such as 45mV or 3V, and press a confirmation key to complete the issuance of the operation instruction.

[0129] S502, if the target value is less than the set threshold, the control module provides a trigger voltage Vt to the first positive input terminal P1 of the first operational amplifier U1B to turn on the switch transistor Q1.

[0130] S503, if the target value is greater than the set threshold, the control module does not provide the trigger voltage Vt to the first positive input terminal P1, so that the switch transistor Q1 remains disconnected.

[0131] S504, the control module determines a reference voltage based on the target value.

[0132] When the user inputs the desired first voltage VOUT, the control module can determine the required reference voltage based on the above relationship (6), and the control voltage VMCU in the relationship (6) can be a preset known value.

[0133] S505, the control module provides a reference voltage to the second positive input terminal P4 of the second operational amplifier U2B.

[0134] The embodiment of the present application also provides a control module, which includes a memory and a processor. The memory stores a computer program. When the computer program runs on the processor, the control module executes Figure 4 or Figure 5 The method shown.

[0135] The present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, Figure 4 or Figure 5 The method shown.

[0136] The present application also provides a computer program product, including a computer program, which is executed by a processor to implement Figure 4 or Figure 5 The method shown.

Claims

1. A very low voltage stabilizing circuit, It is characterized in that include: A voltage output node, used to output a first voltage; a control module, which provides a control voltage based on an operation instruction of a user, and controls the first voltage by causing the control voltage to act on the circuit, wherein the operation instruction carries a target value of the first voltage; a voltage stabilizing module, which is used to discharge the leakage voltage acting on the voltage output node, and comprises a first discharge resistor and a switch transistor, wherein the first discharge resistor and the switch transistor are connected in series between the voltage output node and the ground potential; A voltage acquisition module, whose input end is connected to the voltage output node and whose output end is connected to the control module, so as to transmit an acquisition voltage to the control module, wherein the acquisition voltage is positively correlated with the voltage at the input end of the voltage acquisition module; The voltage stabilizing module comprises a first op amp, wherein the first op amp has a first negative input terminal connected to the voltage acquisition module, a first positive input terminal connected to the control module, and a first output terminal connected to the gate of the switch transistor, wherein the first output terminal is configured to: output a first high level signal in response to a voltage of the first positive input terminal being higher than a voltage of the first negative input terminal, and output a first low level signal in response to a voltage of the first positive input terminal being lower than a voltage of the first negative input terminal; The switch transistor is configured to be turned on in response to the first high level signal and turned off in response to the first low level signal; The control module is configured to: in response to the target value being less than a set threshold, provide a trigger voltage to the first positive input terminal to turn on the switching transistor; in response to the target value being greater than the set threshold, not provide a trigger voltage to the first positive input terminal to turn off the switching transistor.

2. The circuit according to claim 1, It is characterized in that The control module is configured to control the switch transistor to be turned on in a pulsed manner in response to the target value being smaller than the set threshold.

3. The circuit according to claim 1, It is characterized in that The control module is further configured to adjust the control voltage based on the collected voltage.

4. The circuit according to claim 2, It is characterized in that The control module is configured to provide the trigger voltage to the first positive input terminal in a pulsed manner in response to the target value being smaller than the set threshold value, so as to turn on the switch transistor in a pulsed manner.

5. The circuit according to claim 1, It is characterized in that The voltage stabilizing module further includes a second bleeder resistor connected in series between the voltage output node and the ground potential, and the resistance of the second bleeder resistor is greater than that of the first bleeder resistor.

6. The circuit according to claim 1, It is characterized in that Also includes: A voltage source configured to output an initial voltage with an adjustable magnitude based on the control of the control module; a step-down module, comprising an input terminal connected to the output terminal of the voltage source and an output terminal connected to the voltage output node at the same potential, and configured to step down the initial voltage based on the control of the control module, so as to output the first voltage smaller than the initial voltage from the output terminal of the step-down module; a voltage regulating module, comprising a second op amp, a first resistor, a second resistor and a third resistor, wherein the first resistor and the second resistor are connected in series between the output terminal of the step-down module and the ground potential, one end of the third resistor is connected between the first resistor and the second resistor, and the other end is connected to the control module to obtain the control voltage from the control module, the second op amp has a second positive input terminal for receiving a reference voltage, a second negative input terminal connected between the first resistor and the second resistor, and a second output terminal connected to the control module, and the second output terminal is configured to output a second high level signal in response to a voltage of the second positive input terminal being higher than a voltage of the second negative input terminal, and output a second low level signal in response to a voltage of the second positive input terminal being lower than a voltage of the second negative input terminal; Wherein, the control module is configured as follows: In response to the second high level signal, controlling the voltage source to increase the initial voltage, and / or controlling the voltage reduction module to reduce the voltage reduction amplitude of the initial voltage; In response to the second low level signal, the voltage source is controlled to lower the initial voltage, and / or the voltage reduction module is controlled to increase the voltage reduction amplitude of the initial voltage.

7. The circuit according to claim 6, It is characterized in that The step-down module includes a switch device, a capacitor, an inductor and a freewheeling diode; The switch device and the inductor are connected in series between the input terminal and the output terminal of the buck module, and the control module is connected to the control terminal of the switch device to control the conduction frequency and duty cycle of the switch device; The freewheeling diode is connected between the upstream end of the inductor and the ground potential, and the anode of the freewheeling diode faces the ground potential; The capacitor is connected between the downstream end of the inductor and the ground potential; The voltage acquisition module comprises a fourth resistor and a fifth resistor connected in series between the voltage output node and the ground potential, and the output end of the voltage acquisition module is led out from between the fourth resistor and the fifth resistor.

8. A method for stabilizing ultra-low voltage, It is characterized in that Applied to the circuit as claimed in claim 6 or 7, the method comprises: The control module receives the operation instruction of the user; If the target value is less than the set threshold, the control module provides a trigger voltage to the first positive input terminal to turn on the switch transistor; If the target value is greater than the set threshold, the control module does not provide a trigger voltage to the first positive input terminal to keep the switch transistor turned off; The control module determines a control voltage based on the target value; The control module provides the control voltage to the third resistor.

9. A control module, It is characterized in that The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program runs on the processor, the control module executes the method as claimed in claim 8.

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