Test fixture for verifying short circuit and overcurrent of power supply chip

Abstract

The utility model relates to the technical field of power supply chip testing, in particular to a test fixture for verifying short circuit and overcurrent of a power supply chip. Comprising a PCB which is provided with a power supply chip seat used for installing a power supply chip to be tested; the power supply chip seat is provided with six pins, one pin is a power supply input pin, is connected with the first terminal J1, and is connected with filter capacitors C1 and C2 in a circuit, and the other ends of the filter capacitors C1 and C2 are grounded and are used for providing a stable input power supply. The utility model provides a rapid and simple power supply chip overcurrent and short circuit test scheme, materials can be verified in advance, and the risk of damage to an equipment board caused by the fact that the power supply chip needs to bear overcurrent and short circuit current when the performance of the power supply chip needs to be verified after the power supply chip is loaded on the board in the research and development design stage is avoided.

Description

Technical Field

[0001] This utility model relates to the field of power chip testing technology, specifically a test fixture for verifying short-circuit overcurrent of power chips. Background Technology

[0002] In electronic product circuit boards, the stability of power supply chip performance is a crucial indicator of product quality. To ensure the long-term normal operation of the power supply chip, it is necessary to verify that the chip will not burn out under conditions such as short circuits or overcurrents, and that it can resume normal operation after the abnormal conditions have ended. If overcurrent or short circuit tests are performed after the power supply chip is mounted on the board, large currents and voltages will inevitably appear in the circuit, which may cause irreversible damage to surrounding electronic components. Therefore, verifying the abnormal recovery performance of the power supply chip before it is used on the board is a problem that needs to be solved. Utility Model Content

[0003] This invention addresses the technical problems existing in the prior art by providing a test fixture for verifying short-circuit overcurrent of power chips, thus solving the technical problem of how to verify the abnormal recovery performance of power chips before they are put on the board for use.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0005] A test fixture for verifying short-circuit overcurrent of a power supply chip is provided, comprising:

[0006] A PCB board, wherein the PCB board is provided with a power chip socket for mounting the power chip to be tested;

[0007] The power chip socket has six pins, one of which is the power input pin, connected to the first terminal J1, and has filter capacitors C1 and C2 connected in the circuit. The other end of the filter capacitors C1 and C2 is grounded to provide a stable input power.

[0008] Pin 2 is the enable EN pin, which is connected to pin 1 through voltage divider resistor R1 to control the startup state of the power chip;

[0009] Pin 3 is the ground pin, which is directly connected to ground and used for stable grounding of the chip;

[0010] Pin 4 is the FB feedback circuit pin. It is connected in parallel to the output DC voltage terminal through resistor R2 and capacitor C4 in the feedback peripheral circuit, and in series with resistor R3. The other end of resistor R3 is grounded to realize the power chip feedback control to stabilize the output voltage.

[0011] Pin 5 is the LX switch pin, connected to inductor L1, used for filtering and rectification to ensure a stable output voltage;

[0012] Pin 6 is the BST pin, which is connected to pin 5 through bootstrap capacitor C3 to improve the driving capability of the LX pin;

[0013] A capacitor C5 is used as a filter capacitor at the output power supply terminal. One end is connected to the output voltage and the other end is grounded to ensure a clean output voltage.

[0014] A transistor Q1 has its collector connected to the output voltage terminal, its base connected to the external control circuit Control A, and its emitter grounded. It is used to realize external control of the output voltage and to simulate overcurrent and short circuit conditions.

[0015] The second terminal J2 is connected to the output voltage terminal for outputting test results or connecting to external circuits.

[0016] Furthermore, the capacitance values ​​of the filter capacitors C1 and C2 are both 22μF, which are used to filter out high-frequency noise at the power input terminal and ensure the stability of the input power supply.

[0017] Furthermore, the voltage divider resistor R1 has a resistance of 100K ohms and is used to control the enable voltage of the power chip to ensure that the chip can start under preset conditions.

[0018] Furthermore, the resistor R2 and capacitor C4 form a feedback circuit to control the output voltage of the power chip, so as to ensure that the output voltage remains stable under different load conditions.

[0019] Furthermore, the inductor L1 has an inductance of 2.2μH and is used to filter and rectify the LX switch pin, ensuring the stability of the output voltage under abnormal conditions.

[0020] Furthermore, the transistor Q1 is an SOT-23 type NPN transistor, and the connection between its base and the external control circuit Control A is used to control the experimental parameters of short circuit and overcurrent tests. The experimental parameters include the control of short circuit time and the magnitude of overload current.

[0021] Furthermore, the test fixture also includes an output voltage terminal connected to the second terminal J2. The voltage terminal is connected to the external circuit under test and is used to output a test signal and verify the recovery capability of the power chip after a short circuit and overcurrent.

[0022] The beneficial effects of this utility model are: This utility model provides a quick and simple test scheme for overcurrent and short circuit of power chips, which can verify materials in advance and avoid the risk of damage to the equipment board caused by overcurrent and short circuit when verifying the performance of power chips after they have been installed on the board during the research and development stage.

[0023] This invention allows for the regulation of external load current, enabling overcurrent testing of power supply chips and the control of circuit short circuits and recovery through level adjustment. It is a device capable of multiple, rapid, and effective verifications. This invention is suitable for product development stages, featuring a simple circuit, fewer components, and reusability; it reduces testing costs while improving testing efficiency. Attached Figure Description

[0024] Figure 1 This is the test circuit diagram of this utility model. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0028] The present invention provides the following preferred embodiments:

[0029] Existing performance verification tests for power chips often consider their load-bearing capacity, such as maximizing their output current carrying capacity to see how much load they can withstand, or conducting long-term load tests. However, this ignores the fact that during the use of power chips on our circuit boards, they are prone to abnormal situations such as overcurrent and output short circuits caused by accidental touches by testers. We need to consider the chip's recovery capability when the circuit malfunctions. Existing conventional overcurrent and short-circuit measurement methods can only perform current overload or output current short-circuit tests on the prototype after the power chip is mounted on the board. While the test results are straightforward, the large current of short-circuit overcurrents poses a significant risk of causing irreversible damage to components and chips on the prototype board, or even destroying the board itself. This invention addresses these shortcomings by providing a test fixture for verifying short-circuit and overcurrent of power chips. This external test fixture verifies in advance whether the chip can recover to normal operating conditions after undergoing destructive experiments such as overcurrent or short circuits during operation.

[0030] Specifically, such as Figure 1 As shown, this utility model provides a test fixture for verifying short-circuit overcurrent of a power chip, including a PCB board. The PCB board is provided with a power chip socket, a first terminal J1, a second terminal J2, capacitors C1, C2, C3, C4, and C5, resistors R1, R2, and R3, a transistor Q1, and an inductor L1. The power chip socket has 6 pins. Pin 1 is the power input pin, connected to the first terminal J1, with filter capacitors C1 and C2 connected in the middle of its circuit, and the other ends of C1 and C2 are grounded; pin 2 is the enable pin (EN), connected to pin 1 through a voltage divider resistor R1; pin 3 is the ground pin (pi). Pin 1 is directly connected to ground; pin 4 is the FB feedback circuit pin, connected in parallel to the output DC voltage terminal through resistor R2 and capacitor C4 in the feedback peripheral circuit, and also in series with R3, the other end of which is grounded; pin 5 is the LX switch pin, connected to inductor L1 for filtering and rectification, providing a stable output voltage; pin 6 is the BST pin, connected to pin 5 through a bootstrap capacitor C3, with capacitor C5 serving as the filter capacitor for the output power supply, one end connected to the output voltage and the other end grounded; the collector of transistor Q1 is connected to the output voltage, and the base is connected to the external control circuit. A. The emitter is grounded; finally, the second terminal J2 is connected to the output voltage terminal; the capacitance of capacitor C1 is 22uF, the capacitance of capacitor C2 is 22uF, the capacitance of capacitor C3 is 1uF, the capacitance of capacitor C4 is 22uF, the capacitance of capacitor C5 is 22uF, the resistance of resistor R1 is 100K ohms, the resistance of resistor R2 is 20K ohms, the resistance of resistor R3 is 40K ohms, the inductance of inductor L1 is 2.2uH, and the transistor Q1 is an SOT-2 type NPN transistor.

[0031] The working principle of this utility model is as follows: An external DC power supply is connected to terminal J1 of the fixture plate. Turning on the DC power supply outputs a 12V DC power supply, which is connected to the VIN pin of the power chip to power it. Capacitors C1 and C2 are connected to the input power supply and grounded to filter out noise and glitches, providing a clean power supply. Resistor R1 is connected in series between the VIN and EN pins. Adjusting its resistance value can adjust the EN enable signal to change the power-on sequence. The GND pin is normally grounded. Pin 5 is the LX power pulse pin. After filtering by inductor L1, a stable DC power supply is obtained. The output power through inductor L1 is connected to the power feedback pin FB through resistor R2 and capacitor C4 in parallel. FB is then connected to ground through resistor R3. This circuit is a feedback circuit used to monitor the stability of the entire power output system. The LX pin is connected to the BST pin through bootstrap capacitor C3. Capacitor C5 is connected to the output voltage, with the other end grounded, which can filter the output voltage. Simultaneously, a transistor Q1 is connected in parallel with capacitor C5. The base of Q1 is connected to the external control circuit Control. A, the high or low level is controlled by an external circuit, and finally the output voltage is connected to an external electronic load through the second terminal J2. The electronic load is used to control overcurrent.

[0032] When using this device for verification, first solder the power supply chip to be tested onto the power chip socket. Currently, the MPS MP1653GTF-Z DC power supply chip is used for verification. First, turn on the DC input power and input 12V voltage to VIN through the first terminal J1. After adjustment by the power supply chip and peripheral circuitry, a 3.3V DC voltage will be output. This filtered 3.3V voltage is connected to the DC electronic load through the second terminal J2. At this point, adjust the tap current of the electronic load. If, when it rises to 3A, a stable 3.3V power supply cannot be maintained, it indicates that the power supply chip is in an overcurrent state. Then, reduce the tap current to 2.5A, and the power supply chip will work normally again. In this way, we can perform repeated overcurrent tests by controlling the overcurrent time and overcurrent cycle. When we need to perform a short-circuit test, initially the external control circuit... When controller A is at a low level, transistor Q1 is off. When the external control level is high, transistor Q1 turns on and conducts. At this time, the output voltage is directly pulled low, short-circuiting the circuit. Therefore, the entire circuit, including the power supply chip, is in a short-circuit state. We can control whether the power supply chip is short-circuited by controlling the level of controller A. We can perform cyclic testing to verify the recovery capability of the power supply chip after a short circuit, thus achieving short-circuit testing of the power supply chip. This invention is simple to implement, low in cost, and highly cost-effective. It is suitable for the product development stage and provides a low-cost, easy-to-operate solution.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A test fixture for verifying short-circuit overcurrent of a power supply chip, characterized by, The utility model relates to a test fixture for power supply chip, comprising: a PCB board, which is provided with a power supply chip seat for mounting a power supply chip to be tested; the power supply chip seat has six pins, wherein pin 1 is a power supply input pin connected with a first terminal J1 and has filter capacitors C1 and C2 connected in the circuit, the other end of the filter capacitors C1 and C2 is grounded, for providing stable input power supply; pin 2 is an enable EN pin connected with pin 1 through a voltage dividing resistor R1, for controlling the starting state of the power supply chip; pin 3 is a ground ping pin directly connected with the ground, for stable grounding of the chip; pin 4 is an FB feedback circuit pin, which is connected in parallel with a resistor R2 and a capacitor C4 in the feedback peripheral circuit to an output DC voltage end, and is connected in series with a resistor R3, the other end of the resistor R3 is grounded, for realizing feedback control of the power supply chip to stabilize the output voltage; pin 5 is an LX switch pin connected with an inductor L1, for filtering and rectifying to ensure stable output voltage; pin 6 is a BST pin connected with pin 5 through a bootstrap capacitor C3, for improving the driving capability of the LX pin; a capacitor C5 as an output power supply end filter capacitor, one end connected with the output voltage, the other end connected with the ground, for pure output voltage; a transistor Q1, the collector electrode of which is connected to the output voltage end, the base electrode is connected to an external control circuit Control A, and the emitter electrode is grounded, for realizing external control of the output voltage and simulating overcurrent and short circuit conditions; a second terminal J2 connected to the output voltage end, for outputting test results or connecting external circuits.

2. The test fixture of claim 1, wherein, The filter capacitors C1 and C2 have a capacitance value of 22 μF, for filtering high-frequency noise at the power supply input end to ensure stable input power supply.

3. The test fixture of claim 1, wherein, The voltage dividing resistor R1 has a resistance value of 100K ohms, for controlling the enable voltage of the power supply chip to ensure that the chip can start under preset conditions.

4. The test fixture of claim 1, wherein, The resistor R2 and the capacitor C4 form a feedback circuit, for realizing control of the output voltage of the power supply chip to ensure that the output voltage remains stable under different load conditions.

5. The test fixture of claim 1, wherein, The inductor L1 has an inductance value of 2.2 μH, for realizing filtering and rectifying of the LX switch pin to ensure stable output voltage under abnormal conditions.

6. The test fixture of claim 1, wherein, The transistor Q1 is an SOT-23 type NPN transistor, the connection of the base electrode with the external control circuit Control A is for controlling experimental parameters of short circuit and overcurrent tests, the experimental parameters include control of short circuit time and size of overload current.

7. The test fixture of claim 1, wherein, The test fixture further comprises an output voltage end connected with the second terminal J2, the voltage end is connected with an external circuit to be tested, for outputting test signals and verifying the recovery capability of the power supply chip after short circuit and overcurrent.

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