Quick starting circuit suitable for wide-range input voltage and power supply

Abstract

The invention discloses a quick start circuit adapting to wide-range input voltage and a power supply. The quick start circuit comprises a quick start module, a power supply module, a main control chip, a subsequent main circuit and a quick start turn-off module which are connected in sequence. By adopting the mode that the N-channel depletion type MOS voltage stabilizing units are connected in series, input voltage is shared among the N-channel depletion type MOS voltage stabilizing units, a single device is prevented from bearing too high voltage, higher input voltage bearing capacity is achieved, the limitation that the withstand voltage of a traditional fast start integrated chip is smaller than 700V is broken through, and the fast start integrated chip has the advantages of being simple in structure and convenient to use. And the method is suitable for wider high-voltage input application scenes. In addition, through the combination mode of the N-channel depletion type MOS voltage stabilization unit and the quick start-up turn-off module, the power loss under high-voltage input can be greatly reduced, and the energy efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and particularly to a fast startup circuit and a power supply adapted to a wide range of input voltages. Background Art

[0002] In AC (Alternating Current)-DC (Direct Current) and DC-DC power modules, a fast startup circuit is used to shorten the startup time of the module, so that the input voltage can directly supply power to the main control chip through the fast startup circuit, thereby quickly starting the power supply. The fast startup schemes of related technologies mainly include a series startup resistor scheme, a fast startup integrated chip scheme, an enhanced MOS (MOSFET, Metal Oxide Semiconductor Field Effect Transistor)+ startup resistor scheme, and a depletion MOS+ startup resistor scheme, but these schemes all have certain defects.

[0003] Specifically, the series startup resistor scheme directly connects a startup resistor in series at the input end, allowing current to flow through the resistor and supply power to the main control chip. This makes the scheme have large losses under high-voltage input, affecting the energy efficiency of the system. The fast startup integrated chip scheme has a high integration level, but is limited by the withstand voltage ability, usually with a withstand voltage less than 700V, and cannot be applied to application scenarios with higher input voltages. As shown in the appendix Figure 1 The enhanced MOS+ startup resistor scheme shown turns off the startup path through an enhanced MOS transistor after startup to reduce losses. However, enhanced MOS transistors with high withstand voltage (>600V) have a high cost. At the same time, the gate requires a driving resistor, and the number of devices is large, occupying a large PCB area, increasing the overall design cost. The high withstand voltage depletion MOS scheme uses a depletion MOS for startup without an additional driving resistor, but there are few suppliers of depletion MOS with high withstand voltage (>600V), and the cost is high (for example, the price of an 850V depletion MOS is about 2.9 yuan, while the price of a 600V depletion MOS is about 0.3 yuan), which limits its popularity in practical applications.

[0004] Therefore, when the input voltage range is relatively wide (0 - above 700V), the existing fast startup schemes all have their own disadvantages and need to be improved. Summary of the Invention

[0005] The main purpose of the present invention is to propose a fast startup circuit and a power supply adapted to a wide range of input voltages, aiming to at least solve the technical problems such as large losses and narrow input voltage range existing in the startup circuits of related technologies.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] In the first aspect of the present invention, there is provided a fast startup circuit adapted to a wide range of input voltages, including a fast startup module, a power supply module, a main control chip, a subsequent main circuit, and a fast startup shutdown module connected in sequence. The fast startup unit includes a plurality of N-channel depletion MOS voltage stabilization units in series; the input end of the fast startup module is used to receive a first input voltage input by an input source, and the plurality of N-channel depletion MOS voltage stabilization units in series in the fast startup module are used to output a second input voltage to the power supply module, and the power supply module is used to store the second input voltage and transmit a third input voltage to the main control chip; wherein, the main control chip is used to output a control signal to the subsequent main circuit when the third input voltage is greater than a preset startup voltage threshold, and the subsequent main circuit outputs a shutdown signal to the fast startup shutdown module, and the fast startup shutdown module is used to control the fast startup module to be in a shutdown state according to the shutdown signal.

[0008] Based on the first aspect, the fast startup module further includes a first current limiting resistor, and the first current limiting resistor is electrically connected between the input source and the N-channel depletion MOS voltage stabilization unit.

[0009] Based on the first aspect, the N-channel depletion MOS voltage stabilization unit includes an N-channel depletion MOS transistor, a voltage regulator device, and a second current limiting device; the drain of the N-channel depletion MOS transistor is used to receive the first input voltage, the source of the N-channel depletion MOS transistor is electrically connected to the next N-channel depletion MOS transistor or the power supply module, the gate of the N-channel depletion MOS transistor is simultaneously electrically connected to one end of the second current limiting device and one end of the voltage regulator device, the other end of the voltage regulator device is grounded, and the other end of the second current limiting device is electrically connected to the next N-channel depletion MOS transistor or the power supply module.

[0010] Based on the first aspect, the voltage regulator device is a zener diode for providing a gate voltage, the cathode of the zener diode is electrically connected to the gate of the N-channel depletion MOS transistor, and the anode of the zener diode is grounded.

[0011] Based on the first aspect, the second current limiting device is a second current limiting resistor, and the second current limiting resistor is electrically connected between the gate of the N-channel depletion MOS transistor and the zener diode and is used to limit the gate current.

[0012] Based on the first aspect, the power supply module is a power supply capacitor, one end of which is electrically connected to the main control chip, the subsequent main circuit, and the output end of the target N-channel depletion-type MOS voltage regulator unit, and the other end of the power supply capacitor is grounded; wherein the target N-channel depletion-type MOS voltage regulator unit is an N-channel depletion-type MOS voltage regulator unit at the last position among multiple N-channel depletion-type MOS voltage regulator units in series.

[0013] Based on the first aspect, the subsequent main circuit includes an anti-reverse diode and a main circuit power supply winding, the anode of the anti-reverse diode is electrically connected to one end of the power supply capacitor, the main control chip, and the output end of the target N-channel depletion-type MOS voltage regulator unit, the cathode of the anti-reverse diode is electrically connected to one end of the main circuit power supply winding and the input end of the fast start-up shutdown module, and the other end of the main circuit power supply winding is grounded.

[0014] On the basis of the first aspect, the fast startup shutdown module includes an enhanced N-channel MOS tube, a third current limiting device, a second gate resistor and a shutdown signal holding capacitor, the source of the enhanced N-channel MOS tube is grounded, the drain of the enhanced N-channel MOS tube is electrically connected to the target N-channel depletion MOS voltage regulator unit, the gate of the enhanced N-channel MOS tube is electrically connected to one end of the shutdown signal holding capacitor and one end of the second gate resistor at the same time, the other end of the second gate resistor is electrically connected to one end of the third current limiting device, the other end of the third current limiting device is simultaneously connected to the cathode of the anti-reverse diode and one end of the main circuit power supply winding, and the other end of the shutdown signal holding capacitor is grounded.

[0015] Based on the first aspect, the third current limiting device is a current limiting resistor, and the current limiting resistor is used to limit the shutdown signal current.

[0016] A second aspect of the present invention provides a power supply, comprising a device body and a fast start-up circuit adapted to a wide range of input voltages as described in the first aspect.

[0017] The fast start-up circuit and power supply adapted to a wide range of input voltages of the present invention adopt a method of connecting multiple N-channel depletion-type MOS voltage regulator units in series, so that the input voltage is shared among the multiple N-channel depletion-type MOS voltage regulator units, avoiding a single device from being subjected to excessively high voltages, thereby achieving a higher input voltage tolerance, breaking through the limitation that the withstand voltage of the traditional fast start-up integrated chip is less than 700V, and is applicable to a wider range of high-voltage input application scenarios. In addition, through the combination of the N-channel depletion-type MOS voltage regulator unit and the fast start-up shutdown module, the loss under high-voltage input can be greatly reduced, and the energy efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative work, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic circuit connection diagram corresponding to the enhanced MOS + series resistance technical solution in the related art;

[0020] Figure 2 It is a schematic module connection diagram of the fast start circuit adapted to a wide range of input voltages provided by the embodiments of the present application;

[0021] Figure 3 It is a specific schematic circuit connection diagram of each module of the fast start circuit in the embodiments of the present application;

[0022] Figure 4 It is a specific schematic circuit connection diagram of each module of the fast start circuit in the embodiments of the present application;

[0023] Figure 5 It is a timing diagram obtained by simulating the fast start circuit in the embodiments of the present application using simulation software.

[0024] The realization of the object of the present invention, its functional characteristics and advantages will be further described with reference to the embodiments and the drawings. Detailed Embodiments

[0025] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] It should be noted that related terms such as "first", "second", etc. can be used to describe various components, but these terms do not limit the components. These terms are only used to distinguish one component from another. For example, without departing from the scope of the present invention, the first component can be called the second component, and similarly, the second component can also be called the first component. The term "and / or" refers to any combination of one or more of the related items and the described items.

[0027] Please refer to Figure 1, which shows the enhanced MOS + series resistance technical solution in the related art. In this technical solution, it mainly consists of a current-limiting resistor, a driving resistor, a high-voltage withstand enhanced MOSFET, and a turn-off circuit. Although this solution can turn on the quick start path through the MOSFET turn-off and reduce part of the power consumption, there are still the following main disadvantages: 1) A large number of devices, occupying a large PCB area: This solution requires multiple series driving resistors (R10 - R14) and current-limiting resistors (R8 - R9) for voltage division and current limitation to drive the high-voltage withstand enhanced MOSFET (Q5). 2) Large power loss under high-voltage input: During the start-up stage, the input voltage is directly applied to the series current-limiting resistor. According to P = V2 / R, when the high-voltage input (such as above 800V), the power consumption of the current-limiting resistor rises sharply, causing large heat loss and affecting the system efficiency. Since the series resistor continuously consumes energy, even after the MOSFET is turned off, part of the leakage current will still cause additional power loss and reduce the overall energy efficiency. 3) High cost of high-voltage withstand enhanced MOSFET: The enhanced MOSFET with high voltage withstand (such as above 600V) is more expensive. Compared with the depletion-type MOSFET solution, the cost is higher (for example, the 600V-class MOSFET is much more expensive than the same-level depletion-type MOS). The high-voltage MOSFET requires a large safety margin and also requires a driving resistor for gate current limitation, further increasing the cost and complexity. 4) Complex driving and limited response speed: Since the enhanced MOSFET needs a specific gate driving voltage to conduct, when the input voltage is high, the selection of the driving resistor needs to comprehensively consider gate voltage division and charging time, resulting in increased design difficulty. Under high-voltage input conditions, the response speed of the driving circuit may be limited, affecting the start-up time and reducing the system start-up efficiency.

[0028] To solve the above technical problems, please refer to Figure 2 , the embodiment of the present application provides a fast start-up circuit adapted to a wide range of input voltages, which includes a quick start-up module 20, a power supply module 30, a main control chip 40, a subsequent main circuit 50, and a quick start-up turn-off module 60 connected in sequence. The quick start-up unit 20 includes a plurality of N-channel depletion-type MOS voltage stabilization units 202 in series.

[0029] Specifically, when the fast start-up circuit is working, the input end of the quick start-up module 20 is used to receive the first input voltage VIN input by the input source 10. The plurality of N-channel depletion-type MOS voltage stabilization units 202 in series in the quick start-up module 20 jointly bear the first input voltage and output the second input voltage to the power supply module 30. The power supply module 30 is used to store the second input voltage and transmit the third input voltage to the main control chip 40.

[0030] When the third input voltage is greater than the preset startup voltage threshold (indicating that the power supply module 30 has successfully converted and stored the electrical energy provided by the input source 10, and the main control chip 40 has the voltage condition for normal operation), the main control chip is used to output a control signal to the subsequent main circuit 50. The subsequent main circuit 50 outputs a shutdown signal to the fast startup shutdown module 60. The fast startup shutdown module 60 is used to control the fast startup module 20 to be in a shutdown state according to the shutdown signal (this shutdown signal indicates that the fast startup module 20 enters the shutdown state, thus stopping its operation, ensuring the stability of the circuit and avoiding over-reliance on the fast startup circuit). And when the third input voltage is less than the preset startup voltage threshold (indicating that the power supply module 30 has not stored enough electrical energy and the main control chip 40 still cannot operate normally), at this time, the main control chip 40 will not output a control signal, that is, the subsequent main circuit 50 will not output a shutdown signal, and the fast startup module 20 will continue to operate to ensure continuous power supply to the power supply module 30 until the third input voltage reaches or exceeds the startup voltage threshold. This can ensure the stable operation of the system during the startup phase and avoid abnormal operation caused by insufficient power supply.

[0031] It should be noted that the output of the shutdown signal indicates that the main circuit has been able to operate stably and no longer requires the assistance of the fast startup circuit, ensuring the stability and efficiency of the power supply system.

[0032] In addition, it should also be noted that the fast startup module 20 and the fast startup shutdown module 60 constitute a fast startup circuit. When the fast startup shutdown module 60 controls the fast startup module 20 to be in a shutdown state according to the shutdown signal, that is, the fast startup channel is shut down, indicating that the startup is completed, and at this time, multiple N-channel depletion-mode MOS voltage stabilizing units 202 in series jointly bear the input voltage.

[0033] In the embodiment of the present application, since the fast startup module 20 will be shut down after the startup is completed, no additional loss will be generated, and multiple N-channel depletion-mode MOS voltage stabilizing units jointly bear the input voltage. Therefore, depletion-mode MOS with lower withstand voltage can be selected, greatly reducing the cost, and at the same time, the input voltage range can also be broadened. More specifically, in the embodiment of the present application, by adopting the method of connecting multiple N-channel depletion-mode MOS voltage stabilizing units in series, the input voltage is shared among multiple N-channel depletion-mode MOS voltage stabilizing units, avoiding a single device from bearing too high a voltage, thereby achieving a higher input voltage withstand capacity, breaking through the limitation that the withstand voltage of traditional fast startup integrated chips is less than 700V, and being applicable to a wider range of high-voltage input application scenarios.

[0034] Please refer to Figure 3 , the fast startup module further includes a first current-limiting resistor R1, and the first current-limiting resistor R1 is electrically connected between the input source 10 and the N-channel depletion-mode MOS voltage stabilizing unit 202.

[0035] Specifically, during the process of the input source 10 supplying power to the quick startup module 20, the first current-limiting resistor R1 is used to control the current flowing into the N-channel depletion MOS voltage stabilizing unit 202 (playing a role in current limiting), preventing excessive current at the moment of startup and protecting circuit components. Moreover, through the first current-limiting resistor R1, the inrush current during the startup process can be reduced, enabling the circuit to achieve a more stable voltage conversion. Additionally, to a certain extent, it can also share a part of the input voltage, further optimizing the working state of the MOS voltage stabilizing unit 202 and improving its stability and reliability. That is, through the first current-limiting resistor R1, the quick startup module 20 can maintain stable startup within a wider input voltage range, effectively reduce power loss, and improve the voltage withstand capacity and operating life of the system.

[0036] In an alternative embodiment of the present embodiment, the number of N-channel depletion MOS voltage stabilizing units 202 is two, and each includes an N-channel depletion MOS transistor (Q4, Q5), a voltage regulator device (U1, U4), and a second current-limiting device (R2, R3).

[0037] Specifically, in the N-channel depletion MOS voltage stabilizing unit 202, the drain of the N-channel depletion MOS transistor is used to receive the first input voltage. The source of the N-channel depletion MOS transistor is electrically connected to the next N-channel depletion MOS transistor or the power supply module. The gate of the N-channel depletion MOS transistor is simultaneously electrically connected to one end of the second current-limiting device and one end of the voltage regulator device. The other end of the voltage regulator device is grounded, and the other end of the second current-limiting device is electrically connected to the next N-channel depletion MOS transistor or the power supply module.

[0038] Correspondingly, when the number of N-channel depletion MOS voltage stabilizing units 202 is two, the working principle is as follows: When the input voltage is turned on, both N-channel depletion MOSs are in the conducting state. The input voltage quickly charges the power supply module (power supply capacitor CVDD) through the current-limiting resistor R1. CVDD quickly rises to the main control chip startup threshold VDD1 after time t1. Subsequently, the chip starts to generate waves and work, and the power supply winding starts to supply power to CVDD, clamping it at VDD2. At the same time, the power supply winding sends a turn-off signal to the gate of the enhancement-mode N MOS Q3, Q3 conducts, pulling down the gate voltage of the depletion-mode MOS Q5. At this time, the driving voltage across Q5G-S is -VDD2, turning off Q5, thereby disconnecting the quick startup circuit. Subsequently, the source voltage of the high-side depletion-mode MOS Q4 starts to rise to the regulated voltage value V of the voltage regulator U1 ZCD1 and conducts it. The gate voltage of Q4 is clamped at V ZCD1 , and the source voltage of Q4 continues to rise. When the driving voltage across Q4G-S is less than the negative voltage turn-off threshold V of Q4 th after that, Q4 disconnects. Subsequently, the source voltage of Q4 starts to drop, but the driving voltage across Q4G-S also immediately becomes greater than Vth , a negative feedback process is formed, and finally a dynamic balance is reached. The connection point of the high-side and low-side depletion MOS finally stabilizes at V ZCD1 -V th . Finally, the withstand voltage V ds1 borne by the low-side depletion MOS Q5 is V ZCD1 -V th -V DD2 . The withstand voltage V ds2 borne by the high-side depletion MOS Q4 is Vin - V ZCD1 +V th . Therefore, by selecting zener diodes with different V ZCD1 , the input voltage can be distributed across the two depletion MOSs.

[0039] That is, in this embodiment, through the series connection of two N-channel depletion MOS voltage regulation units 202, the voltage borne by a single MOS transistor can be effectively reduced, and the overall withstand voltage capacity can be improved. At the same time, based on the coordinated cooperation of the voltage regulator components (U1, U4) and the second current limiting components (R2, R3), it is ensured that the entire fast startup module 20 can be stably started under a wide range of input voltages, improving the system reliability and efficiency.

[0040] It should be noted that the value of the first current limiting resistor R1 can be jointly determined according to the input voltage, the capacitance value of the power supply capacitor, and the startup time requirement, and the number of the first current limiting resistors is calculated according to the power derating requirement at the moment of startup; the resistance values of the depletion MOS gate drive resistors R2 and R3 should not be too large or too small. The voltage across the drive resistor is equal to about -1V, the turn-off threshold of the depletion MOS. If the resistance value is too small, the loss of the zener diode will become larger. If the resistance value is too large, the current flowing through the zener diode will be too small to trigger the zener diode to work.

[0041] In an alternative embodiment of this embodiment, the voltage regulator components are zener diodes (U1, U4) for providing gate voltage. The cathode of the zener diode is electrically connected to the gate of the N-channel depletion MOS transistor, and the anode of the zener diode is grounded.

[0042] Specifically, through the zener diode setting, when the input voltage is high, the zener diodes (U1, U4) keep the gate voltage constant, preventing the MOS transistor from being unstable in its working state due to voltage fluctuations.

[0043] In an alternative embodiment of the present embodiment, the second current limiting device is a second current limiting resistor (R2, R3), and the second current limiting resistor is electrically connected between the gate of the N-channel depletion MOS transistor and the zener diode. On the one hand, the gate current is limited by the second current limiting resistor to avoid damage to the zener diode and the MOSFET caused by excessive current. On the other hand, a voltage dividing circuit is formed together with the zener diode to ensure that the gate voltage is maintained near the regulated voltage value of the zener diode, so that the MOSFET is in a suitable working state.

[0044] In an alternative embodiment of the present embodiment, the power supply module is a power supply capacitor CVDD. One end of the power supply capacitor is electrically connected to the main control chip (G1 terminal), the subsequent main circuit (U2, L1), and the output terminal of the target N-channel depletion MOS voltage regulation unit at the same time, and the other end of the power supply capacitor is grounded.

[0045] Among them, the target N-channel depletion MOS voltage regulation unit is the N-channel depletion MOS voltage regulation unit at the end position among multiple N-channel depletion MOS voltage regulation units in a series relationship (that is, the last-stage MOS transistor, and the output voltage of this MOS transistor is directly used as the input of the power supply module 30 and is finally stored and regulated by the power supply capacitor CVDD). That is, in this embodiment, the power supply module 30 uses the power supply capacitor CVDD as the main energy storage element to store the stable voltage output by the N-channel depletion MOS voltage regulation unit 202 and supply electrical energy to the main control chip 40 and the subsequent main circuit, thereby reducing the influence of power supply fluctuations on the main control chip and the subsequent circuit and enabling the entire fast start-up circuit to adapt to a wider input voltage range.

[0046] In an alternative embodiment of the present embodiment, the subsequent main circuit includes an anti-reverse diode U2 and a main circuit power supply winding L1. The anode of the anti-reverse diode is electrically connected to one end of the power supply capacitor, the main control chip, and the output terminal of the target N-channel depletion MOS voltage regulation unit at the same time, and the cathode of the anti-reverse diode is electrically connected to one end of the main circuit power supply winding L1 and the input terminal of the fast start-off module at the same time, and the other end of the main circuit power supply winding L1 is grounded.

[0047] Specifically, the subsequent main circuit is composed of an anti-reverse diode U2 and a main circuit power supply winding L1. When the main control chip 40 starts to work, the subsequent main circuit 50 also starts to work (the main circuit power supply winding L1 outputs a turn-off signal, and the turn-off signal is provided by the voltage on the main circuit power supply winding L1), and the power supply capacitor CVDD will store energy by the voltage output by the main circuit power supply winding L1 and no longer rely on the fast start-up circuit, further improving the stability and quality of the power supply.

[0048] Among them, the anti - reverse diode U2 plays a role in preventing reverse current. That is, when there is a reverse current in the circuit (for example, when the output voltage direction in the main - circuit power - supply winding L1 changes), the anti - reverse diode will cut off, blocking the current loop and preventing the voltage on the power - supply capacitor CVDD from being discharged, thereby improving the stability of the power supply.

[0049] In an alternative implementation of this embodiment, the fast startup - shutdown module includes an enhanced N - channel MOS transistor Q3, a third current - limiting device R4, a second gate resistor R5, and a shutdown - signal holding capacitor C1. The source of the enhanced N - channel MOS transistor is grounded. The drain of the enhanced N - channel MOS transistor is electrically connected to the target N - channel depletion - type MOS voltage - regulating unit. The gate of the enhanced N - channel MOS transistor is electrically connected to one end of the shutdown - signal holding capacitor C1 and one end of the second gate resistor R5 at the same time. The other end of the second gate resistor R5 is electrically connected to one end of the third current - limiting device R4. The other end of the third current - limiting device R4 is electrically connected to the cathode of the anti - reverse diode U2 and one end of the main - circuit power - supply winding L1 at the same time. The other end of the shutdown - signal holding capacitor C1 is grounded.

[0050] When the fast - startup circuit is in the normal working state (the fast - startup module 20 is turned on), in the initial stage of system power - on, the main - control chip 40 has not reached the preset startup - voltage threshold, and the fast - startup module 20 needs to maintain the conducting state. At this time, the gate voltage of the enhanced N - channel MOS transistor Q3 in the fast - startup - shutdown module is relatively low, keeping it closed to ensure that the target N - channel depletion - type MOS voltage - regulating unit 202 continues to be powered.

[0051] As the power - supply voltage gradually rises, until the power - supply capacitor CVDD in the subsequent main circuit is charged to the preset startup - voltage threshold, the main - control chip 40 starts to work to execute the control logic and issue a control signal (indicating that the system is ready to enter the next stage). Then, the subsequent main circuit 50 starts based on the control signal, and the main - circuit power - supply winding L1 starts to work to supply power (providing a stable voltage for the circuit), and this voltage is transmitted as a shutdown signal to the fast - startup - shutdown module 60.

[0052] At this time, the shutdown signal causes the gate voltage of the enhanced N - channel MOS transistor Q3 in the fast - startup - shutdown module 60 to rise, prompting it to conduct, directly grounding the output terminal of the target N - channel depletion - type MOS voltage - regulating unit 202, thereby forcibly shutting down the fast - startup module 20. The third current - limiting device R4 and the second gate resistor R5 ensure a smooth change in the gate voltage, avoiding misoperation caused by current overshoot.

[0053] When the fast start-up circuit is in the shutdown state, the shutdown signal holding capacitor C1 continues to maintain the gate voltage after the MOS tube Q3 is turned on, so that it remains turned on for a period of time, ensuring that the fast start-up module 20 is completely turned off and will not be mistakenly turned on due to short-term voltage fluctuations. At the same time, the shutdown holding time of the fast start-up circuit can be adjusted by adjusting the size of the holding capacitor C1.

[0054] In an optional implementation of this embodiment, the third current limiting device is a current limiting resistor R4. Specifically, the current limiting resistor R4 limits the current of the shutdown signal, ensuring that the fast startup shutdown module 60 has a stable current control capability during operation. In addition, it can also ensure that the enhanced N-channel MOS tube Q3 can be stably restored to the off state after the shutdown signal is cancelled, further improving the reliability of the circuit.

[0055] See also Figure 4 In this embodiment, three N-channel depletion MOS voltage regulator units 202 are connected in series. By using three voltage regulator units in series, it is suitable for 1KV <Vin<1.5KV(即第一输入电压处于1KV和1.5KV之间的情况),其具体工作原理与前述具体实施例相同,但本实施例改变了稳压管的连接方式,前述实施例的稳压管阳极都是接地,若本实施例的三个稳压管阳极仍然都接地,则对最高压一级的稳压管稳压值要求很高,但通常稳压管的最大稳压值为400V,需要多个稳压管串联才能达到要求。因此在本实施例中高压侧的稳压管阳极接在下一级耗尽型MOS的源级,可以降低对稳压管稳压值的要求,方便选型。

[0056] It should also be noted that if the input voltage is higher (greater than 1.5KV), more depletion-type MOS voltage regulator units can be connected in series to share the input voltage.

[0057] See also Figure 5 , which shows the timing diagram obtained by using simulation software to build the above embodiment, and the entire startup process is consistent with the above principle description.

[0058] Specifically, the following conclusions can be drawn from the simulation results: the fast start-up module 20 works as expected, and gradually establishes a stable power supply voltage VDD1 after the input voltage is applied. The main circuit power supply winding successfully outputs a shutdown signal after VDD1 reaches the threshold, and the fast start-up module 20 is shut down, proving that the working mechanism of the fast start-up shutdown module 60 is correct. The voltage sharing function of the MOS voltage regulator unit 202 is verified, and the changes of Vds1 and Vds2 are in line with the voltage regulation theory, indicating that the series design of the N-channel depletion-type MOS voltage regulator unit effectively improves the voltage resistance. VDD2 eventually enters a stable state, indicating that the power supply module 30 successfully completes the startup and supplies power normally, ensuring long-term and reliable operation of the system.

[0059] In summary, the simulation timing diagram verifies the reliability and stability of the quick start circuit of the present invention under a wide range of input voltages, proving that it can effectively reduce power consumption, improve voltage resistance and enhance system stability, meeting the needs of high-voltage input application scenarios.

[0060] The embodiment of the present application also provides a power supply, including a device body and a fast start-up circuit of the above embodiments that is adaptable to a wide range of input voltages.

[0061] The fast start-up circuit and power supply adapted to a wide range of input voltages of the present invention adopt a method of connecting multiple N-channel depletion-type MOS voltage regulator units in series, so that the input voltage is shared among the multiple N-channel depletion-type MOS voltage regulator units, avoiding a single device from being subjected to excessively high voltages, thereby achieving a higher input voltage tolerance, breaking through the limitation that the withstand voltage of the traditional fast start-up integrated chip is less than 700V, and is applicable to a wider range of high-voltage input application scenarios. In addition, through the combination of the N-channel depletion-type MOS voltage regulator unit and the fast start-up shutdown module, the loss under high-voltage input can be greatly reduced, and the energy efficiency can be improved.

[0062] In addition, the present invention also has the following beneficial effects:

[0063] 1. Compared with the existing startup scheme of series startup resistor, the present invention can greatly reduce the loss under high voltage input by combining depletion MOS + shut-down fast startup circuit.

[0064] 2. Compared with the integrated fast startup chip, the present invention can greatly broaden the input voltage range by connecting the depletion-type MOS voltage regulator circuit in series, so that the startup can meet the derating requirements.

[0065] 3. Compared with the solution of realizing fast startup by using a single depletion-mode MOS, the present invention can reduce the withstand voltage requirement of the depletion-mode MOS and significantly reduce the device cost by connecting multiple depletion-mode MOS in series.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fast startup circuit adapted to a wide range of input voltages, characterized in that, It includes a quick startup module, a power supply module, a main control chip, a subsequent main circuit, and a quick startup shutdown module connected in sequence. The quick startup module includes a plurality of N-channel depletion MOS voltage stabilizing units in series connection; The input end of the quick startup module is used to receive the first input voltage input by the input source. The plurality of N-channel depletion MOS voltage stabilizing units in series connection in the quick startup module are used to output the second input voltage to the power supply module. The power supply module is used to store the second input voltage and transmit the third input voltage to the main control chip; Among them, when the third input voltage is greater than a preset startup voltage threshold, the main control chip is used to output a control signal to the subsequent main circuit. The subsequent main circuit outputs a shutdown signal to the quick startup shutdown module. The quick startup shutdown module is used to control the quick startup module to be in a shutdown state according to the shutdown signal.

2. The fast start-up circuit adapted to a wide range of input voltages as described in claim 1, characterized in that The quick startup module further includes a first current limiting resistor, and the first current limiting resistor is electrically connected between the input source and the N-channel depletion MOS voltage stabilizing unit.

3. The fast startup circuit adapted to a wide range of input voltages according to claim 1, wherein, The N-channel depletion MOS voltage stabilizing unit includes an N-channel depletion MOS transistor, a voltage stabilizing device, and a second current limiting device; The drain of the N-channel depletion MOS transistor is used to receive the first input voltage. The source of the N-channel depletion MOS transistor is electrically connected to the next N-channel depletion MOS transistor or the power supply module. The gate of the N-channel depletion MOS transistor is simultaneously electrically connected to one end of the second current limiting device and one end of the voltage stabilizing device. The other end of the voltage stabilizing device is grounded or connected to the source of the next N-channel depletion MOS transistor. The other end of the second current limiting device is electrically connected to the next N-channel depletion MOS transistor or the power supply module.

4. The fast startup circuit for adapting to a wide range of input voltages according to claim 3, wherein, The voltage stabilizing device is a zener diode for providing a gate voltage. The cathode of the zener diode is electrically connected to the gate of the N-channel depletion MOS transistor, and the anode of the zener diode is grounded.

5. The fast start-up circuit adapted to a wide range of input voltages according to claim 4, characterized in that, The second current limiting device is a second current limiting resistor, and the second current limiting resistor is electrically connected between the gate of the N-channel depletion MOS transistor and the zener diode and is used to limit the gate current.

6. The fast startup circuit adapted to a wide range of input voltages as described in claim 1, characterized in that The power supply module is a power supply capacitor. One end of the power supply capacitor is simultaneously electrically connected to the main control chip, the subsequent main circuit, and the output end of the target N-channel depletion MOS voltage stabilizing unit. The other end of the power supply capacitor is grounded; Among them, the target N-channel depletion MOS voltage stabilizing unit is the N-channel depletion MOS voltage stabilizing unit at the end position among the plurality of N-channel depletion MOS voltage stabilizing units in series connection.

7. The fast startup circuit adapted to a wide range of input voltages according to claim 6, characterized in that, The subsequent main circuit includes an anti-reverse diode and a main circuit power supply winding. The anode of the anti-reverse diode is simultaneously electrically connected to one end of the power supply capacitor, the main control chip, and the output end of the target N-channel depletion MOS voltage stabilizing unit. The cathode of the anti-reverse diode is simultaneously electrically connected to one end of the main circuit power supply winding and the input end of the quick startup shutdown module. The other end of the main circuit power supply winding is grounded.

8. The fast startup circuit adapted to a wide range of input voltages according to claim 7, characterized in that, The fast startup and shutdown module includes an enhanced N-channel MOS transistor, a third current limiting device, a second gate resistor, and a shutdown signal holding capacitor. The source of the enhanced N-channel MOS transistor is grounded. The drain of the enhanced N-channel MOS transistor is electrically connected to the target N-channel depletion-type MOS voltage stabilizing unit. The gate of the enhanced N-channel MOS transistor is electrically connected to one end of the shutdown signal holding capacitor and one end of the second gate resistor at the same time. The other end of the second gate resistor is electrically connected to one end of the third current limiting device. The other end of the third current limiting device is electrically connected to the cathode of the anti-reverse diode and one end of the main circuit power supply winding at the same time. The other end of the shutdown signal holding capacitor is grounded.

9. The fast startup circuit for adapting to a wide range of input voltages according to claim 8, characterized in that, The third current limiting device is a current limiting resistor, and the current limiting resistor is used to limit the shutdown signal current.

10. A power supply, characterized in that, It includes a device body and a fast startup circuit adapted to a wide range of input voltages according to any one of claims 1 to 9.

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