Optimized DC loop stability test circuit and tool

Abstract

The utility model relates to the technical field of power supply testing, in particular to an optimized DC loop stability test circuit and tool, the test circuit comprises a modulator, the modulator is connected with an input voltage Vin; the base electrode of the amplifier is connected with the modulator; the resistor Rinj, the resistor R1 and the resistor R2 are sequentially connected in series, one end of the resistor Rinj is connected to output voltage Vout, one end of the resistor R2 is grounded, and an emitting electrode of the amplifier is connected between the resistor R1 and the resistor R2; the isolation transformer T1 is connected with the resistor Rinj in parallel; the oscilloscope is connected with the isolation transformer T1; the FG end of the oscilloscope is grounded through one side of the isolation transformer T1, and the Ch1 end and the Ch2 end of the oscilloscope are respectively connected to the other side of the isolation transformer T1; the tool plate is good in compatibility, only one tool plate needs to be manufactured, the tool plate can be repeatedly disassembled, assembled and utilized in loop tests of multiple loops and even various samples, and the implementation method is simple and rapid.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply testing, in particular to an optimized DC loop stability testing circuit and tooling. Background Art

[0002] At present, in the R&D and production stage of electronic products, the loop stability test of the internal power supply can provide a high-level reference for the power supply output accuracy and stability in the design stage, which is essential; in order to realize the control loop response test, we need to inject an error signal into the feedback path of the control loop, and this feedback path is the feedback resistor divider network. We need to connect a smaller resistor in series to the feedback loop to inject an error signal.

[0003] In conventional loop stability tests, we usually connect a low-resistance injection resistor (Rinj) in series. Usually, the resistors soldered on the circuit board are very small 0402 or even smaller 0201 chip resistors. If there is no reserved space, you need to cut the board and connect the resistors with flying wires. After connecting the resistors, you need to lead out 4 leads from both ends of the resistors to connect to the isolation transformer and passive probe. This is very time-consuming and labor-intensive, and will increase the risk of board damage. If there are multiple DCDCs that need to be tested, the time will be doubled. Summary of the invention

[0004] The utility model aims at the technical problems existing in the prior art and provides an optimized DC loop stability test circuit and tooling to solve the complex problem of power loop stability test.

[0005] The technical solution of the utility model to solve the above technical problems is as follows:

[0006] Provided is a circuit and tool for optimizing DC loop stability test, the test circuit comprising:

[0007] A modulator, wherein the modulator is connected to an input voltage Vin;

[0008] an amplifier, wherein a base of the amplifier is connected to the modulator;

[0009] A resistor Rinj, a resistor R1 and a resistor R2 are connected in series in sequence, one end of the resistor Rinj is connected to the output voltage Vout, one end of the resistor R2 is grounded, and the emitter of the amplifier is connected between the resistor R1 and the resistor R2;

[0010] an isolation transformer T1 connected in parallel with the resistor Rinj; and

[0011] An oscilloscope connected to the isolation transformer T1;

[0012] The FG terminal of the oscilloscope is grounded through one side of the isolation transformer T1 , and the Ch1 and Ch2 terminals of the oscilloscope are respectively connected to the other side of the isolation transformer T1 .

[0013] Furthermore, the resistance of the resistor Rinj is 5 ohms.

[0014] Furthermore, the test points of the test circuit are located at two ends of the resistor Rinj.

[0015] Furthermore, the resistor Rinj is an injected chip resistor.

[0016] Provided is a DC loop stability optimization test fixture, the test fixture comprising:

[0017] Breadboard;

[0018] An injection resistor mounted on the breadboard;

[0019] Lead 1 and lead 2 are respectively connected to two ends of the injection resistor, and the lead 1 and lead 2 are soldered on the breadboard; and

[0020] Two wires are respectively welded to the welding points of the lead 1 and the lead 2, and the two wires are respectively connected to two ends of the resistor Rinj.

[0021] Furthermore, the injection resistor has a resistance of 10 ohms.

[0022] Furthermore, the injection resistor is a metal film resistor.

[0023] The beneficial effects of the utility model are:

[0024] 1. Soldering and blowing on the tiny chip resistors on the test board is time-consuming and laborious, and it is very easy to damage the board. Using this tool instead of soldering and blowing on the test circuit board is very time-saving and effective.

[0025] 2. Good compatibility. Only one set of tool boards needs to be prepared, which can be repeatedly disassembled and assembled for multi-channel loop testing or even loop testing of multiple samples. The implementation method is simple and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural block diagram of the utility model. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model.

[0028] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0029] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0031] The utility model provides the following preferred embodiments:

[0032] refer to Figure 1As shown, a test fixture is provided that can simplify the stability of the back-end loop of the DCDC chip. The tiny chip resistors are replaced by more stable, reliable and easy-to-operate metal film resistors, which are integrated on the panel circuit board. Wiring points A, B, C, and D should be reserved for direct connection with the test fixture. It is only necessary to introduce the leads into the feedback loop to be measured for direct testing. This tool greatly shortens the test time each time, is not easy to damage the test board, and can be reused many times.

[0033] A test tool for optimizing DC loop stability test, including a circuit breadboard, an injection resistor connected to an isolation transformer, a metal film resistor with high precision, stable performance, simple and lightweight structure is used to replace a tiny chip resistor that is not easy to operate, and reserved connection points A, B, C, D connected to a test instrument, and a relatively soft wire for connecting the upper end of the feedback resistor and the output end of the test board. The wire can be made of copper wire. It is understandable that the wire can also be implemented using other conductive substitutes.

[0034] The device is light and easy to make. The isolation transformer and the passive probe can be quickly and accurately connected to both ends of the injection resistor, replacing the complex and vulnerable blow welding and flying wire operations on the sample to be tested. It only needs to connect the leads to the feedback loop to be tested, and it can be reused, greatly improving the efficiency of testing the DC loop.

[0035] The specific production steps of this utility model are as follows:

[0036] Step 1: Use a panel circuit board, which does not need to be too large, 6cm*8cm in size is enough, and connect the injection resistor required for the test to the circuit board. You can use a more common metal film resistor on the market. The resistance value should be as small as possible, about 10Ω is best;

[0037] Step 2: After the wiring positions are reserved at both ends of the injection resistor, bend and solder them to the breadboard. Figure 1 Points A, B, C, and D shown must ensure that the clips of the isolation transformer and the passive probe can be stably clamped without loosening;

[0038] Step 3: Lead out a conductive wire from the connection between the injection resistor and the breadboard. It can be a copper wire. One end of the wire is connected to the upper end of the feedback loop resistor to be tested, and the other end is connected to the output voltage end. It should be noted that the upper end of the feedback resistor and the output voltage are disconnected at this time.

[0039] Step 4: Operate the oscilloscope to directly conduct the test. After completing the loop test, just disconnect the lead connected to the system on the tool board and connect it to the next loop test.

[0040] The beneficial effects of the present invention are specifically embodied in that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An optimized DC loop stability test circuit, characterized in that: The test circuit comprises: A modulator, wherein the modulator is connected to an input voltage Vin; an amplifier, wherein a base of the amplifier is connected to the modulator; A resistor Rinj, a resistor R1 and a resistor R2 are connected in series in sequence, one end of the resistor Rinj is connected to the output voltage Vout, one end of the resistor R2 is grounded, and the emitter of the amplifier is connected between the resistor R1 and the resistor R2; an isolation transformer T1 connected in parallel with the resistor Rinj; and An oscilloscope connected to the isolation transformer T1; The FG terminal of the oscilloscope is grounded through one side of the isolation transformer T1 , and the Ch1 and Ch2 terminals of the oscilloscope are respectively connected to the other side of the isolation transformer T1 .

2. The optimized DC loop stability test circuit according to claim 1, characterized in that: The resistance value of the resistor Rinj is 5 ohms.

3. The optimized DC loop stability test circuit according to claim 1, characterized in that: The test points of the test circuit are located at two ends of the resistor Rinj.

4. The optimized DC loop stability test circuit according to claim 1, characterized in that: The resistor Rinj is an injected chip resistor.

5. An optimized DC loop stability test tool, characterized in that: The test fixture comprises the optimized DC loop stability test circuit according to any one of claims 1 to 4, and the test fixture further comprises: Breadboard; An injection resistor mounted on the breadboard; Lead 1 and lead 2 are respectively connected to two ends of the injection resistor, and the lead 1 and lead 2 are soldered on the breadboard; and Two wires are respectively welded to the welding points of the lead 1 and the lead 2, and the two wires are respectively connected to two ends of the resistor Rinj.

6. The optimized DC loop stability test tool according to claim 5, characterized in that: The injection resistor has a resistance of 10 ohms.

7. The optimized DC loop stability test tool according to claim 5, characterized in that: The injection resistor is a metal film resistor.

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