Power-on instant chip power supply starting selection circuit

Abstract

The utility model discloses a power-on instant chip power supply starting selection circuit, which relates to the technical field of electronics and comprises an input voltage source, a power supply cut-off delay sub-circuit, a power supply selection sub-circuit and a direct-current voltage source module. The input voltage source is a direct-current voltage source, is connected with the power supply cut-off delay sub-circuit and is used for supplying power; the power supply cut-off delay sub-circuit is also connected with the power supply selection sub-circuit and is used for supplying power to a control chip in a direct-current voltage source module at the rear end within the delay time after the circuit is powered on and started and stopping power supply after the delay time; the power supply selection sub-circuit is also connected with the DC voltage source module, and is used for selecting a voltage with a higher voltage value between the first output voltage of the power supply cut-off delay sub-circuit and the second output voltage of the DC voltage source module to supply power to the DC voltage source module. The power supply circuit can normally supply power to the chip when the circuit is just started, and has strong practicability.

Description

Technical Field

[0001] The utility model relates to the field of electronic technology, in particular to a power-on instant chip power supply start selection circuit. Background Art

[0002] In the internal architecture of contemporary electronic devices, the power supply requirements of components are becoming increasingly sophisticated, and low voltage ranges (usually a few volts to more than ten volts) are generally required to meet the energy consumption and efficiency standards of high-performance chips. However, the input power of these devices often comes from a high-voltage AC power grid (such as 220VAC) or a higher DC voltage, which brings challenges to the initial startup phase of the system. At startup, since the power management system of the entire machine has not yet been fully established, finding a suitable low-voltage source to activate the key control chip becomes the primary problem in the design.

[0003] Traditional solutions, such as using transformers to step down the voltage, external power modules or high-power linear regulators for pre-start power supply, can achieve voltage conversion, but these methods have obvious defects. First, the cost issue is an important link that cannot be ignored, especially for large-scale production and cost-sensitive products. Transformers and large step-down modules not only have high material costs, but also increase assembly complexity and production cycle; secondly, these solutions need to occupy a certain volume in physical space, which will lead to low space utilization of the board; thirdly, the high energy consumption during the power conversion process is converted into heat dissipation, which will lead to a decrease in the overall efficiency of the system and complex heat dissipation design, affecting the reliability and environmental adaptability of the product.

[0004] In summary, how to solve the problem of low practicality of the traditional chip power supply solution during power-on startup has become a technical problem that needs to be solved urgently in this field. Utility Model Content

[0005] The main purpose of the utility model is to provide a power-on instant chip power supply startup selection circuit, aiming to solve the technical problem of low practicality of the traditional chip power supply solution during power-on startup.

[0006] To achieve the above object, the utility model provides a power-on instant chip power supply startup selection circuit, the power-on instant chip power supply startup selection circuit comprises an input voltage source, a power supply cut-off delay sub-circuit, a power supply selection sub-circuit and a DC voltage source module;

[0007] The input voltage source is a DC voltage source, connected to the power supply cut-off delay subcircuit, and used for power supply;

[0008] The power supply cut-off delay subcircuit is also connected to the power supply selection subcircuit, and is used to supply power to the DC voltage source module at the rear end within the delay time after the circuit is powered on, and stop supplying power after the delay time;

[0009] The power supply selection subcircuit is also connected to the DC voltage source module, and is used to select a higher voltage value between the first output voltage of the power supply cut-off delay subcircuit and the second output voltage of the DC voltage source module to power the DC voltage source module.

[0010] Optionally, the power supply cut-off delay subcircuit includes: a first resistor, a second resistor, a first capacitor, a transistor, a voltage regulator diode and a first diode;

[0011] The first end of the first resistor is connected to the input voltage source, and the second end of the first resistor is connected to the emitter of the transistor;

[0012] A first end of the second resistor is connected to the base of the transistor, and a second end of the second resistor is connected to the anode of the first diode;

[0013] The cathode of the first diode is connected to the input voltage source;

[0014] A first end of the first capacitor is connected to a second end of the second resistor, and a second end of the first capacitor is grounded;

[0015] The collector of the triode is connected to the output end of the power supply cut-off delay subcircuit;

[0016] The cathode of the voltage stabilizing diode is connected to the output end of the power supply cut-off delay sub-circuit, and the anode of the voltage stabilizing diode is grounded.

[0017] Optionally, the first resistor is used to control the current value of the output end of the power supply cut-off delay sub-circuit;

[0018] The first capacitor is used to provide a voltage for the cutoff of the triode;

[0019] The second resistor is used to form a charging circuit with the first capacitor and is used to control the delay time of the circuit;

[0020] The triode is used as a switch to control the power supply of the output end of the power supply cut-off delay subcircuit;

[0021] The voltage stabilizing diode is used to determine the output voltage of the output end of the power supply cut-off delay sub-circuit.

[0022] Optionally, the power supply cut-off delay subcircuit further includes:

[0023] A first diode, wherein the first diode is connected between the second end of the second resistor and the DC input voltage source module;

[0024] The first diode is used to provide a fast discharge path for the first capacitor.

[0025] Optionally, the power supply cut-off delay subcircuit further includes:

[0026] a second capacitor, wherein a first end of the second capacitor is connected to the output end of the power supply cut-off delay sub-circuit, and a second end of the second capacitor is grounded;

[0027] The second capacitor is used as a filter capacitor.

[0028] Optionally, the power supply selection subcircuit includes:

[0029] a second diode, wherein an anode of the second diode is connected to an output end of the power supply cut-off delay subcircuit, and a cathode of the second diode is connected to an output end of the power supply selection subcircuit;

[0030] A third diode, wherein the anode of the third diode is connected to the output end of the DC voltage source module, and the cathode of the third diode is connected to the output end of the power supply selection sub-circuit.

[0031] Optionally, when the power supply cut-off delay sub-circuit is powered on, the DC voltage source module has no output voltage, and the first output voltage supplies power to the DC voltage source module through the second diode.

[0032] Optionally, after the power supply cut-off delay sub-circuit is powered on, the DC voltage source module outputs a second output voltage, and the power supply selection sub-circuit selects a higher voltage between the first output voltage and the second output voltage through the second diode or the third diode to power the DC voltage source module.

[0033] Optionally, after the delay time, the transistor is disconnected, and the second output voltage supplies power to the DC voltage source module through the third diode.

[0034] Optionally, the input voltage source is an AC voltage source, and the power-on instant chip power supply startup selection circuit further includes:

[0035] A full-bridge rectifier voltage-divider filter sub-circuit, one end of which is connected to the input voltage source, and the other end is connected to the power supply cut-off delay sub-circuit, for rectifying the AC input voltage into a DC voltage;

[0036] A voltage-dividing resistor is connected between the full-bridge rectifier voltage-dividing filter sub-circuit and the power supply cut-off delay sub-circuit, and is used to divide the DC voltage.

[0037] In the technical solution of the utility model, a chip power supply startup selection circuit is designed at the moment of power-on. The high-power step-down circuit in the chip power supply startup selection circuit at the moment of power-on will stop working after the delay time expires, and only works for a few seconds at power-on startup, thereby reducing the loss and heat generation of the entire machine. In addition, the circuit improvement solution in the present application requires a low-cost circuit and can be applied to DC input scenarios, so that the chip can be powered normally when the circuit is just started, and it is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0039] Figure 1 This is a circuit diagram of a transformer plus rectification and filtering solution;

[0040] Figure 2 The schematic diagram of the circuit for the step-down power supply solution;

[0041] Figure 3 It is a power schematic diagram of a high-power semiconductor linear step-down solution;

[0042] Figure 4 This is a schematic diagram of the circuit framework of the chip power supply startup selection circuit at the moment of power-on of the utility model;

[0043] Figure 5 This is a specific circuit diagram of the chip power supply startup selection circuit at the moment of power-on of the utility model.

[0044] Description of Figure Numbers:

[0045] Label name Label name 10 Input voltage source 20 Power supply cut-off delay subcircuit 30 Power supply selection subcircuit 40 DC voltage source module R1 First resistor R2 Second resistor C1 First capacitor Q1 triode ZD1 Zener diode D1 The first diode C2 Second capacitor D2 The second diode D3 The third diode

[0046] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0048] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0049] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0050] In the internal architecture of contemporary electronic devices, the power supply requirements of components are becoming increasingly sophisticated, and low voltage ranges (usually a few volts to more than ten volts) are generally required to meet the energy consumption and efficiency standards of high-performance chips. However, the input power of these devices often comes from a high-voltage AC power grid (such as 220VAC) or a higher DC voltage, which brings challenges to the initial startup phase of the system. At startup, since the power management system of the entire machine has not yet been fully established, finding a suitable low-voltage source to activate the key control chip becomes the primary problem in the design.

[0051] Traditional solutions, such as using transformers to step down the voltage, external power modules or high-power linear regulators for pre-start power supply, can achieve voltage conversion, but these methods have obvious defects. In the transformer plus rectifier filter solution, please refer to Figure 1 , Figure 1 This is a circuit diagram of the transformer plus rectifier filter solution. In the transformer plus rectifier filter solution, the AC input is transformed by the transformer and rectified by diodes and capacitors for output. This solution is only applicable to AC input, and has high cost and low board space utilization. In the step-down power supply solution, please refer to Figure 2 , Figure 2 This is a circuit diagram of a step-down power supply solution. In the step-down power supply solution, the DC or AC input is stepped down through the power module and then output. This method is costly and has large energy losses. For high-power semiconductor linear step-down solutions, please refer to Figure 3 , Figure 3 This is a circuit diagram of a high-power semiconductor linear step-down solution. In the high-power semiconductor linear step-down solution, the circuit continues to suffer losses during operation and generates severe heat.

[0052] In summary, how to solve the problem of low practicality of the traditional chip power supply solution during power-on startup has become a technical problem that needs to be solved urgently in this field.

[0053] In view of the above problems, in the technical solution of the utility model, a chip power supply startup selection circuit is designed at the moment of power-on. The chip power supply startup selection circuit at the moment of power-on can reduce the input voltage to the voltage required by the DC voltage source module by setting a power supply cut-off delay sub-circuit when the circuit is just powered on, so as to power the DC voltage source module, and select a higher voltage value between the first output voltage of the power supply cut-off delay sub-circuit and the second output voltage of the DC voltage source module through the power supply selection sub-circuit to power the DC voltage source module, thereby ensuring the subsequent stable operation of the DC voltage source module. In addition, the circuit cost required for the circuit improvement scheme in the present application is low, and can be applied to the scenario of DC input, so that it can normally power the chip when the circuit is just started, and it is more practical.

[0054] Reference Figure 4 As shown, Figure 4 The schematic diagram of the circuit framework of a power-on instant chip power supply startup selection circuit proposed by the utility model, the power-on instant chip power supply startup selection circuit comprises an input voltage source 10, a power supply cut-off delay sub-circuit 20, a power supply selection sub-circuit 30 and a DC voltage source module 40;

[0055] The input voltage source 10 is a DC voltage source, connected to the power supply cut-off delay sub-circuit 20, for supplying power;

[0056] The power supply cut-off delay subcircuit 20 is also connected to the power supply selection subcircuit 30, and is used to supply power to the rear-end DC voltage source module 40 within the delay time after the circuit is powered on, and stop supplying power after the delay time;

[0057] The power supply selection subcircuit 30 is also connected to the DC voltage source module 40 and is used to select a higher voltage between the first output voltage of the power supply cut-off delay subcircuit 20 and the second output voltage of the DC voltage source module 40 to supply power to the DC voltage source module 40 .

[0058] In this embodiment, the DC voltage source is an external input voltage source 10 of the circuit, which powers the entire circuit. In this example, it must be a DC voltage source, generally a battery or a DC voltage source input. The power supply cut-off delay circuit is the core circuit of this application. The circuit can provide VCCA (the output of the power supply cut-off delay subcircuit 20) to the control chip in the back-end DC voltage source module 40 during the delay time (generally 1 to 3 seconds) when the power is turned on. After the output voltage of the DC voltage source module 40 is successfully established, the output of this circuit is cut off. After that, the DC voltage source module 40 VCC (the output of the power supply selection circuit) is powered by the DC voltage source itself The output VCCB (the output of the DC voltage source module 40) is provided. During the delay time, the power supply selection circuit selects the higher one between VCCA and VCCB as VCC to power the DC voltage source module 40.

[0059] The DC voltage source module 40 is generally the core power supply in the circuit system of the electronic product. After the power supply is started, it is necessary to maintain the power supply of the entire circuit system.

[0060] It should be noted that, in this embodiment, in order to ensure the normal operation of the circuit, VCCA needs to be always greater than or equal to VCCB, and the voltage values ​​of VCCA and VCCB need to be within the power supply voltage range of the chip in the DC voltage source module 40.

[0061] Optionally, in a feasible implementation, please refer to Figure 5 , Figure 5 A specific circuit diagram of the chip power supply startup selection circuit at the power-on moment, the power supply cut-off delay subcircuit 20 includes: a first resistor R1, a second resistor R2, a first capacitor C1, a transistor Q1, a voltage regulator diode ZD1 and a first diode D1;

[0062] A first end of the first resistor R1 is connected to the input voltage source 10, and a second end of the first resistor R1 is connected to the emitter of the transistor Q1;

[0063] A first end of the second resistor R2 is connected to the base of the transistor Q1, and a second end of the second resistor R2 is connected to the anode of the first diode D1;

[0064] The cathode of the first diode D1 is connected to the input voltage source 10;

[0065] A first end of the first capacitor C1 is connected to a second end of the second resistor R2, and a second end of the first capacitor C1 is grounded;

[0066] The collector of the transistor Q1 is connected to the output end of the power supply cut-off delay sub-circuit 20;

[0067] The cathode of the voltage zener diode ZD1 is connected to the output end of the power supply cut-off delay sub-circuit 20 , and the anode of the voltage zener diode ZD1 is grounded.

[0068] In this embodiment, when the DC voltage source is powered on, the circuit charges the capacitor C1 through R1 / Q1 / R2. At the moment of charging, C1 is short-circuited and Q1 is turned on. The input DC voltage source outputs the VCCA voltage to the back-end power supply selection circuit through the current limiting resistor R1 and ZD1. As time goes by, the voltage of the capacitor C1 becomes higher and higher until Q1 is cut off. At this time, the input DC voltage source can no longer output the VCCA voltage to the back-end power supply selection circuit through R1 / ZD1. After the capacitor C1 is fully charged, no current flows through all devices in this circuit during the power-on period of the DC input voltage source 10, and no power loss occurs.

[0069] Furthermore, the first resistor R1 is used to control the current value of the output end of the power supply cut-off delay sub-circuit 20;

[0070] The first capacitor C1 is used to provide a voltage for the cutoff of the transistor Q1;

[0071] The second resistor R2 is used to form a charging circuit with the first capacitor C1 and is used to control the delay time of the circuit;

[0072] The transistor Q1 is used as a switch to control the output end of the power supply cut-off delay sub-circuit 20 to supply power;

[0073] The voltage stabilizing diode ZD1 is used to determine the output voltage of the output terminal of the power supply cut-off delay sub-circuit 20 .

[0074] In this embodiment, the functions of the various components of the circuit are as follows:

[0075] C1: provides voltage for Q1 to cut off;

[0076] R2: C1 charging current limiting resistor. The RC charging circuit composed of C1 and R2 determines the circuit delay time. The delay time must be at least greater than the time it takes for the back-end DC voltage source module 40 to output the normal VCCB voltage value after power-on. The delay time is approximately t=3~5*R2*C1;

[0077] R1: This value determines the supply current value of VCCA. This value is generally a few tenths of the resistance value of R2. The current value is (DC input voltage source 10 voltage value - VCCA) / R1. This current value must be at least greater than the current value when the internal chip of the DC voltage source module 40 is working normally;

[0078] ZD1: determines the output voltage value of VCCA, which is approximately the voltage value of the Zener diode;

[0079] Q1: PNP transistor Q1 is used as a switch to control VCCA to supply power to the back-end power supply selection circuit.

[0080] Furthermore, in a feasible implementation manner, the power supply cut-off delay subcircuit 20 further includes:

[0081] The first diode D1 is used to provide a fast discharge path for the first capacitor C1.

[0082] In this embodiment, a first diode D1 may be further provided in the circuit to provide a fast discharge path for the first capacitor C1. In the circuit, the first diode D1 provides a fast discharge path for the capacitor C1 to prevent circuit failure when the DC voltage source is frequently and rapidly powered on and off.

[0083] Furthermore, in a feasible implementation manner, the power supply cut-off delay subcircuit 20 further includes:

[0084] A second capacitor C2, wherein a first end of the second capacitor C2 is connected to the output end of the power supply cut-off delay sub-circuit 20, and a second end of the second capacitor C2 is grounded;

[0085] The second capacitor C2 is used as a filter capacitor.

[0086] In this implementation, a second capacitor C2 may be connected between the output terminal and the ground in the circuit to serve as a filter capacitor.

[0087] Optionally, the power supply selection subcircuit 30 includes:

[0088] a second diode D2, wherein the anode of the second diode D2 is connected to the output end of the power supply cut-off delay sub-circuit 20, and the cathode of the second diode D2 is connected to the output end of the power supply selection sub-circuit 30;

[0089] A third diode D3 , wherein an anode of the third diode D3 is connected to the output end of the DC voltage source module 40 , and a cathode of the third diode D3 is connected to the output end of the power supply selection sub-circuit 30 .

[0090] In this embodiment, the circuit selects the end with a higher voltage value between VCCA and VCCB through D2 and D3 to supply power to the back-end DC voltage source module 40. This circuit has the following three working states.

[0091] Specifically, when the power cut-off delay sub-circuit 20 is powered on, the DC voltage source module 40 has no output voltage, and the first output voltage supplies power to the DC voltage source module 40 through the second diode D2.

[0092] In this embodiment, the power supply cut-off delay circuit outputs a normal VCCA voltage just after being powered on, and the DC voltage source module 40 also just starts working after being powered on and does not output a normal VCCB voltage. VCCB is much smaller than the VCCA voltage value, and VCCA continues to supply power to the DC voltage source module 40 through the isolation diode D2.

[0093] After the power supply cut-off delay subcircuit 20 is powered on, the DC voltage source module 40 outputs a second output voltage, and the power supply selection subcircuit 30 selects a higher voltage between the first output voltage and the second output voltage to power the DC voltage source module 40 through the second diode D2 or the third diode D3.

[0094] In this embodiment, the power supply cut-off delay circuit continues to output the normal VCCA voltage before the delay time is up, and the DC voltage source module 40 outputs the normal VCCB voltage. At this time, the power supply selection circuit selects the end with a higher voltage value between VCCA and VCCB to supply power to the rear-end DC voltage source module 40 through the isolation diode D2 / D3;

[0095] After the delay time, the transistor Q1 is disconnected, and the second output voltage supplies power to the DC voltage source module 40 through the third diode D3.

[0096] In this embodiment, when the power supply cut-off delay circuit delay time expires, Q1 is disconnected and can no longer output the VCCA voltage, and VCCB continues to supply power to the DC voltage source module 40 through the isolation diode D3.

[0097] Under the condition of no external signal input, the utility model realizes delayed disconnection of input voltage through transistor Q1 and RC circuit, and after the internal control chip of the voltage source works normally, the voltage source outputs a stable voltage to power the chip, and naturally cuts off the original power supply voltage source through the delay circuit, thereby reducing external power supply loss and avoiding the problem of continuous heating. It can also use a minimum of discrete components to build a simple and reliable power supply circuit, solving the problem of no suitable voltage source to power the internal chip when the circuit is powered on.

[0098] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and no further description will be given later. On this basis, the input voltage source 10 is an AC voltage source, and the power-on instant chip power supply startup selection circuit also includes:

[0099] A full-bridge rectifier voltage divider filter sub-circuit, one end of the full-bridge rectifier voltage divider filter sub-circuit is connected to the input voltage source 10, and the other end is connected to the power supply cut-off delay sub-circuit 20, for rectifying the AC input voltage into a DC voltage;

[0100] The voltage dividing resistor is connected between the full-bridge rectifier voltage dividing filter sub-circuit and the power supply cut-off delay sub-circuit 20 and is used to divide the DC voltage.

[0101] In this embodiment, if the input is an AC voltage source, a full-bridge rectifier and voltage divider filter circuit needs to be added before the power supply cut-off delay circuit to rectify and filter the AC input voltage into DC power, and then step it down into the required DC voltage through a resistor divider.

[0102] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0103] The serial numbers of the above-mentioned embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0104] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the utility model in essence or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, including a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the utility model.

[0105] 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 specification and drawings of the present invention, 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 power-on instant chip power supply startup selection circuit, characterized in that: The power-on instant chip power supply startup selection circuit comprises an input voltage source, a power supply cut-off delay subcircuit, a power supply selection subcircuit and a DC voltage source module; The input voltage source is a DC voltage source, connected to the power supply cut-off delay subcircuit, and used for power supply; The power supply cut-off delay subcircuit is also connected to the power supply selection subcircuit, and is used to supply power to the DC voltage source module at the rear end within the delay time after the circuit is powered on, and stop supplying power after the delay time; The power supply selection subcircuit is also connected to the DC voltage source module, and is used to select a higher voltage value between the first output voltage of the power supply cut-off delay subcircuit and the second output voltage of the DC voltage source module to power the DC voltage source module.

2. The power-on instant chip power startup selection circuit as claimed in claim 1, characterized in that: The power supply cut-off delay subcircuit comprises: a first resistor, a second resistor, a first capacitor, a transistor, a voltage regulator diode and a first diode; The first end of the first resistor is connected to the input voltage source, and the second end of the first resistor is connected to the emitter of the transistor; A first end of the second resistor is connected to the base of the transistor, and a second end of the second resistor is connected to the anode of the first diode; The cathode of the first diode is connected to the input voltage source; A first end of the first capacitor is connected to a second end of the second resistor, and a second end of the first capacitor is grounded; The collector of the triode is connected to the output end of the power supply cut-off delay subcircuit; The cathode of the voltage stabilizing diode is connected to the output end of the power supply cut-off delay sub-circuit, and the anode of the voltage stabilizing diode is grounded.

3. The power-on instant chip power startup selection circuit as claimed in claim 2, characterized in that: The first resistor is used to control the current value of the output end of the power supply cut-off delay subcircuit; The first capacitor is used to provide a voltage for the cutoff of the triode; The second resistor is used to form a charging circuit with the first capacitor and is used to control the delay time of the circuit; The triode is used as a switch to control the power supply of the output end of the power supply cut-off delay subcircuit; The voltage stabilizing diode is used to determine the output voltage of the output end of the power supply cut-off delay sub-circuit.

4. The power-on instant chip power startup selection circuit as claimed in claim 3, characterized in that: The first diode is used to provide a fast discharge path for the first capacitor.

5. The power-on instant chip power startup selection circuit as claimed in claim 4, characterized in that: The power supply cut-off delay subcircuit also includes: a second capacitor, wherein a first end of the second capacitor is connected to the output end of the power supply cut-off delay sub-circuit, and a second end of the second capacitor is grounded; The second capacitor is used as a filter capacitor.

6. The power-on instant chip power startup selection circuit as claimed in claim 2, characterized in that: The power supply selection subcircuit comprises: a second diode, wherein an anode of the second diode is connected to an output end of the power supply cut-off delay subcircuit, and a cathode of the second diode is connected to an output end of the power supply selection subcircuit; A third diode, wherein the anode of the third diode is connected to the output end of the DC voltage source module, and the cathode of the third diode is connected to the output end of the power supply selection sub-circuit.

7. The power-on instant chip power startup selection circuit as claimed in claim 6, characterized in that: When the power supply cut-off delay sub-circuit is powered on, the DC voltage source module has no output voltage, and the first output voltage supplies power to the DC voltage source module through the second diode.

8. The power-on instant chip power startup selection circuit as claimed in claim 7, characterized in that: After the power supply cut-off delay subcircuit is powered on, the DC voltage source module outputs a second output voltage, and the power supply selection subcircuit selects a higher voltage between the first output voltage and the second output voltage through the second diode or the third diode to power the DC voltage source module.

9. The power-on instant chip power startup selection circuit as claimed in claim 8, characterized in that: After the delay time, the transistor is disconnected, and the second output voltage supplies power to the DC voltage source module through the third diode.

10. The power-on instant chip power startup selection circuit as claimed in claim 1, characterized in that: The input voltage source is an AC voltage source, and the power-on instant chip power supply startup selection circuit further includes: A full-bridge rectifier voltage-divider filter sub-circuit, one end of which is connected to the input voltage source, and the other end is connected to the power supply cut-off delay sub-circuit, for rectifying the AC input voltage into a DC voltage; A voltage-dividing resistor is connected between the full-bridge rectifier voltage-dividing filter sub-circuit and the power supply cut-off delay sub-circuit, and is used to divide the DC voltage.

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