Brief introduction

Ripple voltage is a voltage fluctuation in the output of a DC power supply, referring to the AC component of the output voltage. Excessive ripple voltage can have an impact on the normal operation of electronic devices, so reducing ripple voltage is an important issue that needs to be addressed in the power supply design process. This article will introduce some commonly used methods to reduce ripple voltage.

1. Filter capacitor
Filter capacitor is a commonly used method to reduce ripple voltage. By selecting an appropriate capacitance value, most of the AC components in the output voltage can be filtered out, thereby reducing the ripple voltage. Generally speaking, the larger the capacitance value, the better the filtering effect. However, it should be noted that a high capacitance value can increase cost and volume, while a low capacitance value may not achieve good filtering results.

2. Increase inductance
Adding inductive components to the DC power output circuit can effectively reduce ripple voltage. Inductive components have the characteristic of exhibiting high impedance to AC current, thus playing a filtering role in circuits. By increasing the number and value of inductive components, the ripple voltage can be further reduced. It should be noted that the selection of inductance components should be optimized according to specific application scenarios and requirements.

3. Use a voltage regulator
A voltage regulator is a commonly used power management component that can provide a stable output voltage. By inputting ripple voltage at the input end of the voltage regulator, a voltage with almost no ripple can be obtained at the output end of the voltage regulator. Regulators typically use feedback control to maintain stable output voltage by continuously adjusting their internal circuits. Choosing a suitable voltage regulator and designing a feedback circuit can effectively reduce ripple voltage.

4. Optimize power supply layout
Reasonable optimization of power supply layout can reduce ripple voltage. Firstly, it is important to separate the high frequency and low-frequency circuits. The interference between high-frequency and low-frequency circuits may lead to an increase in ripple voltage. Secondly, it is important to pay attention to the wiring between the power supply and load, reduce the length of the wiring, and take reasonable isolation measures to reduce crosstalk between the power supply and load, thereby reducing ripple voltage. Finally, a reasonable layout of the ground wire should be carried out to avoid interference
from the ground wire circuit and reduce ripple voltage.

5. Choose a suitable transformer
Transformers are commonly used components in DC power supplies, and selecting the appropriate transformer can reduce ripple voltage. Generally speaking, multi-stage gap technology can be used in transformer design, which increases the magnetic resistance of the iron core by creating gaps on the iron core, thereby increasing the operating frequency
and saturation current of the transformer. This can reduce the ripple voltage of the transformer during operation.

6. Control load changes

The sudden changes and fluctuations in the load can also lead to an increase in ripple voltage, so it is necessary to fully consider and control the changes in the load in the design. Load balancing can be used to reduce the total ripple voltage by designing appropriate load circuits that generate opposite fluctuations in the output voltage. In addition, reasonable control of load variation rate and avoidance of rapid load changes are also effective methods to reduce ripple voltage.

7. Optimize heat dissipation design

The heat generated during the operation of the power supply may also lead to an increase in ripple voltage. Therefore, in the design process, it is necessary to optimize the heat dissipation design to ensure that the operating temperature of the power supply is within a reasonable range. Heat dissipation components such as heat sinks and fans can be used to increase the heat dissipation area and efficiency. Through good heat dissipation design, ripple voltage can be reduced.

8. Reasonably select components
In design, selecting appropriate power components is also a key factor in reducing ripple voltage. For example, choosing a diode with low ripple current and an I0S transistor can reduce switching losses and ripple voltage during switching. Meanwhile, it is important to choose capacitors with low ESR (Equivalent Series Resistance) to reduce the losses and
ripple voltage caused by the internal resistance of the capacitors.

Conclusion
The small ripple voltage is an important issue that needs to be addressed in the power supply design process. This article introduces some commonly used methods, including filtering capacitors, increasing inductance, using voltage regulators, optimizing power supply layout, selecting appropriate transformers, controlling load changes, optimizing heat dissipation design, and selecting components reasonably. In practical applications, appropriate methods can be selected based on specific needs to reduce ripple voltage and improve the stability and reliability of the power supply.