CN-121984329-A - Method, device and medium for determining filter inductance parameters of switching power supply conversion circuit

CN121984329ACN 121984329 ACN121984329 ACN 121984329ACN-121984329-A

Abstract

The embodiment of the application provides a method, a device and a medium for determining filter inductance parameters of a switching power supply conversion circuit. The method comprises the steps of setting two ends of an output filter capacitor at the output end of a switching power supply as sampling points and connecting radio frequency connecting wires to lead ripple signals out of a high-low temperature test box for measurement, so that the ripple amplitude of the output voltage at a preset temperature can be accurately obtained under the condition that the high-low temperature test box is not opened, and when the ripple exceeds the preset output ripple amplitude, inductance and direct current resistance parameters are adjusted by installing a magnetic ring winding inductance at the position of the output filter inductance and adjusting winding turns and/or wire length, so that the output filter inductance parameters meeting ripple indexes are rapidly determined, and the problems that in the prior art, the measurement cannot be carried out simultaneously, the dead halt is easily caused by the fact that the ripple is large in mass production stage, and the repeated version cost is high are solved.

Inventors

ZHOU BO
CHEN HAIZAN
CHEN YULONG

Assignees

长沙金维集成电路股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. A method of determining a filter inductance parameter of a switching power supply switching circuit, the method for a circuit board disposed within a high and low temperature test chamber and containing at least one switching power supply switching circuit, the method comprising: Taking two ends of an output filter capacitor at the output end of the switching power supply conversion circuit as sampling points; The two ends of the output filter capacitor are connected with radio frequency connecting wires, and the radio frequency connecting wires are led out of the high-low temperature test box and connected with a measuring instrument so as to obtain output voltage ripples at the two ends of the output filter capacitor; when the temperature in the high-low temperature test box reaches a preset temperature, acquiring the amplitude of the voltage ripple through the measuring instrument; When the amplitude of the output voltage ripple is larger than the preset output ripple amplitude, installing a magnetic ring winding inductor at the position of an output filter inductor of the switching power supply conversion circuit, and adjusting the inductance and/or direct current resistance of the magnetic ring winding inductor by changing the winding turns and/or the wire length of the magnetic ring winding inductor so as to adjust the output filter inductor parameter of the switching power supply conversion circuit; And taking the corresponding inductance and/or direct current resistance when the preset output ripple amplitude is met as the output filtering inductance parameter of the switching power supply conversion circuit until the output voltage ripple amplitude is smaller than or equal to the preset output ripple amplitude.
2. The method of claim 1, wherein the rf connection line is a coaxial rf line, an inner conductor of the coaxial rf line is connected to an output node of the output filter capacitor, and an outer shielding layer of the coaxial rf line is grounded and connected to a ground sampling point of the output filter capacitor or to a ground point near a ground of the output filter capacitor.
3. The method for determining a filter inductance parameter of a switching power supply switching circuit according to claim 1, wherein the magnetic loop winding inductance comprises a magnetic loop core and a wire wound around the core, and the inductance and/or the direct current resistance of the magnetic loop winding inductance are changed by adjusting the winding number and/or the wire length of the wire so as to change the output filter inductance parameter.
4. The method of determining a filter inductance parameter of a switching power supply switching circuit according to claim 1, further comprising: Before a magnetic ring winding inductor is arranged at the position of the output filter inductor, determining deviation between the output voltage ripple amplitude and the preset output ripple amplitude, wherein the deviation comprises a difference value and/or a proportion exceeding amount of an actual output voltage ripple amplitude and the preset output ripple amplitude, and determining winding turns and/or wire length of the magnetic ring winding inductor based on the deviation.
5. The method of claim 4, wherein the magnetic loop winding inductor has an inductance value of Turns of wire winding Magnetic path length of selected core The following are satisfied: Wherein, the The inductance of the inductor is wound for the magnetic loop, For the equivalent permeability of the magnetic core, For the cross-sectional area of the core, For the number of turns of the wire, For the magnetic path length of the selected core.
6. The method of determining a filter inductance parameter of a switching power supply switching circuit according to claim 1, further comprising: After the number of winding turns and/or the length of the wires of the magnetic ring winding inductance are determined, the output voltage ripple amplitude at two ends of the filter capacitor is estimated based on the working parameters of the switching power supply conversion circuit, and an estimation formula is as follows: Wherein, the For the output voltage ripple amplitude across the output filter capacitor, For the load current correspondingly output by the switching power supply conversion circuit, For the switching frequency of the switching power supply conversion circuit and/or the characteristic frequency of the output ripple, And filtering the capacitance value of the capacitor for the output.
7. The method for determining a filter inductance parameter of a switching power supply switching circuit according to claim 1, wherein the preset output ripple amplitude is set to 5% -10% of the rated output voltage of the switching power supply, and the preset output ripple amplitude is smaller than a maximum ripple threshold allowed by a chip power supply pin in the circuit board.
8. The method of determining a filter inductance parameter of a switching power supply switching circuit of claim 1, further comprising: And after the inductance and/or the direct current resistance corresponding to the preset output ripple amplitude value are used as the output filter inductance parameters of the switching power supply conversion circuit, selecting the packaging inductance corresponding to the inductance and/or the direct current resistance value as the output filter inductance of the circuit board.
9. A switching power supply switching circuit filter inductance parameter determining device, comprising: a memory configured to store instructions; a processor configured to invoke the instructions from the memory and when executing the instructions is capable of implementing the method of determining a switching power supply conversion circuit filter inductance parameter according to any one of claims 1 to 8.
10. A machine-readable storage medium having instructions stored thereon, which when executed by a processor cause the processor to be configured to perform the method of determining a switching power supply conversion circuit filter inductance parameter according to any one of claims 1 to 8.

Description

Method, device and medium for determining filter inductance parameters of switching power supply conversion circuit Technical Field The application relates to the technical field of electronics, in particular to a method, a device and a medium for determining filter inductance parameters of a switching power supply conversion circuit. Background The switching power supply conversion circuit is widely applied to various modules and boards and provides stable power supply for a main control chip, a memory and an interface circuit. As the application scene of the product expands to wide temperature environments such as vehicle-mounted, industrial and outdoor environments, the influence of power output ripple and noise on the stability of the system is remarkable, and the problems of undervoltage reset, dead halt restarting, abnormal communication and the like are easily caused by overlarge ripple, so that the ripple needs to be designed, controlled and verified under the high-low temperature condition. In the prior art, ripple is measured at two ends of an output capacitor by using an oscilloscope probe under normal temperature conditions, and indexes are realized by replacing inductors and capacitors or optimizing layout. However, when the high-low temperature test box is used for verification, the box is inconvenient to open in the test process, the oscilloscope probe is difficult to reliably work in the box, if common leads are adopted for leading out measurement, the loop area is increased, and interference is easy to be introduced, so that measurement distortion is caused. On the other hand, the miniaturization of the board card leads to most of small-package devices at the output end, and the hard probe or temporary welding easily causes the falling of a bonding pad, the damage of an element and even the damage of a probe, so that the height Wen Wenbo is difficult to accurately and repeatedly measure. Even if the normal temperature test is qualified, the ripple wave may be increased at high and low temperatures due to the decrease of the effective capacitance value, the change of ESR, the drift of inductance parameters and the change of loop characteristics, and the problem is often exposed in the trial production or mass production stage, so that reworking modification, re-verification, cycle extension and cost increase are caused. Therefore, a ripple measurement and filter inductance parameter determination scheme suitable for high-low temperature test scenes is needed, real ripple is obtained under the condition that a test box is not opened, filter inductance parameters meeting indexes are rapidly determined, and wide-temperature reliability and mass production consistency are improved. Disclosure of Invention The embodiment of the application aims to provide a method, a device and a medium for determining filter inductance parameters of a switching power supply conversion circuit. To achieve the above object, a first aspect of the present application provides a method for determining a filter inductance parameter of a switching power supply switching circuit, the method being used for a circuit board placed in a high-low temperature test chamber and including at least one switching power supply switching circuit, the method comprising: Taking two ends of an output filter capacitor at the output end of a switching power supply conversion circuit as sampling points; the two ends of the output filter capacitor are connected with radio frequency connecting wires, the radio frequency connecting wires are led out of the high-low temperature test box and connected with a measuring instrument so as to obtain output voltage ripples at the two ends of the output filter capacitor; When the temperature in the high-low temperature test box reaches a preset temperature, the amplitude of the voltage ripple is obtained through a measuring instrument; When the amplitude of the output voltage ripple is larger than the preset output ripple amplitude, installing a magnetic ring winding inductor at the position of an output filter inductor of the switching power supply conversion circuit, and adjusting the inductance and/or direct current resistance of the magnetic ring winding inductor by changing the winding turns and/or the wire length of the magnetic ring winding inductor so as to adjust the output filter inductor parameter of the switching power supply conversion circuit; And taking the corresponding inductance and/or direct current resistance when the preset output ripple amplitude is met as the output filter inductance parameter of the switching power supply conversion circuit until the output voltage ripple amplitude is smaller than or equal to the preset output ripple amplitude. In the embodiment of the application, the radio frequency connecting wire is a coaxial radio frequency wire, an inner conductor of the coaxial radio frequency wire is connected with an output end node of the output filter capacitor, and