How to Solve Noise Issues in Switching Power Supplies
Solution for Noise in Switching Power Supply
Switching power supply is an electronic device that can convert 100V-260V AC power into stable 5V, 12V, 24V DC power. This power supply uses high-frequency switching circuits to turn the input voltage into sparks, thereby achieving efficient voltage reduction. However, the noise generated during the use of switch mode power supplies is a concern for many people. This article will introduce the causes of switch power supply noise and how to take effective measures to reduce switch power supply noise.
Reasons for Noise Generation in Switching Power Supply
1. Magnetic field interference
The high-frequency magnetic field in a switching power supply can interfere with other electronic devices around it, causing electromagnetic radiation noise.
2. Parallel connection of capacitors
The parallel connection of filtering capacitors in switch mode power supplies can also generate noise, which is usually high-frequency noise.
3. Driving voltage
The driving circuit of a switching power supply is a high-frequency circuit. Due to the transmission characteristics of high-frequency signals, the driving voltage will generate radio frequency interference, which will affect the stability of the switching power supply.
4. Inductance leakage magnetic field
Inductance leakage in switch mode power supplies is also one of the causes of noise.
Solution for Noise in Switching Power Supply
1. Reduce parallel noise of capacitors
The parallel connection of capacitors in switch mode power supplies is the main source of high-frequency noise. In order to reduce the noise caused by capacitor parallel connection, the following measures need to be taken:
(1) Using organic electrolytic capacitors: Organic electrolytic capacitors have a relatively small capacitance, and the corresponding noise generated is also small.
(2) Using multiple small capacitance capacitors in parallel: Multiple small capacitance capacitors in parallel can share the noise generated by capacitor parallel connection.
(3) Using an independent power supply: An independent power supply can effectively reduce the noise generated by parallel capacitors.
2. Strengthen shielding
Shielding is an effective noise reduction method, and by using appropriate shielding materials, interference from electronic devices and the surrounding environment can be effectively reduced.
(1) Improve shielding performance: Choose shielding materials with good shielding performance, such as ferromagnetic materials, aluminum foil, copper foil, etc.
(2) Increase shielding layers: When one layer of shielding is insufficient to meet the requirements in critical areas, additional shielding layers can be added on top of the original ones.
3. Reduce driving voltage noise
The driving voltage of a switching power supply is one of the main factors that generate noise. In order to reduce the noise of the driving voltage, the following measures can be taken:
(1) Choosing a suitable power supply: Choosing a power supply with more stable performance can greatly reduce the noise generated by switching power supplies.
(2) Reduce the noise of driving voltage: The noise of driving voltage can be reduced through power filtering capacitors, magnetic beads, torque magnetic rings, TLPI networks, and other methods.
4. Reduce inductor leakage noise
Inductive leakage is also one of the causes of noise in switching power supplies. To reduce the leakage noise of inductors, the following measures can be taken:
(1) Choosing high-quality inductors: Using high-quality raw materials for inductors can greatly reduce the leakage noise of inductors.
(2) Adopting magnetic shielding technology: By using magnetic shielding technology in key areas, the noise generated by inductance leakage can be effectively reduced
