Abstract

The Desktop Power Adapter is widely used in precision electronic fields such as audio-video peripherals and small medical supporting equipment. Low-noise and low-interference power supply is the core premise to ensure clear image and pure sound quality of equipment. With an independent vertical structure far from signal lines, the Desktop Power Adapter effectively reduces coupling interference to precision signal links. The ripple noise, conduction and radiation indicators of the Desktop Power Adapter directly determine the user experience and overseas EMC certification pass rate of terminal products. During foreign trade selection, it is necessary to focus on verifying the EMC test data of the Desktop Power Adapter to ensure stable and compliant export of precision equipment.

I. Principle of Low-Ripple Circuit Design

1. The Desktop Power Adapter optimizes the internal multi-stage filter circuit, strengthens noise suppression, effectively blocks switching noise from transmitting to the output end, greatly reduces power supply background noise, and avoids noise and current sound in audio equipment.

2. The Desktop Power Adapter optimizes switching frequency parameters, reduces high-frequency electromagnetic radiation intensity, weakens signal interference to cameras and video acquisition modules, and eliminates adverse phenomena such as screen flicker, color stripes and image distortion.

3. Adopting a wide-voltage voltage regulation architecture, the Desktop Power Adapter has extremely small output voltage fluctuation under mains voltage changes, avoiding volume jump and screen brightness flicker and greatly improving user experience.

4. The Desktop Power Adapter selects low-ESR capacitors and low-loss power components, achieves ultra-low ripple output while meeting Level VI high energy efficiency standards, and balances noise reduction performance and energy-saving compliance requirements.

II. EMC Electromagnetic Compatibility Optimization Scheme

1. The input end of the Desktop Power Adapter is equipped with an EMI filter network composed of common-mode inductors and X/Y safety capacitors, which efficiently suppresses conducted disturbance, reduces electromagnetic noise released from the power supply to the grid, and stably meets EN 55032 Class B limits.

2. The Desktop Power Adapter adopts partitioned PCB layout with completely separated power loops and signal loops, reduces high-frequency loop area, greatly cuts down spatial radiation interference, and adapts to usage scenarios of precision signal equipment.

3. Equipped with a reliable shell grounding design, the Desktop Power Adapter quickly releases static electricity, improves equipment electrostatic immunity, and avoids equipment crash and signal interruption caused by static shock.

4. The input loop of the Desktop Power Adapter integrates surge protection devices to resist instantaneous grid surge pulses, adapt to complex overseas power grid environments, and fully protect the safety of the power supply and backend precision equipment.

III. Selection and Customization Key Points for Audio and Video Equipment

1. Selecting the Desktop Power Adapter gives priority to verifying measured ripple data. Precision equipment such as high-fidelity audio and high-definition cameras needs customized versions with stricter ripple indicators to ensure signal purity.

2. Verify parameters according to EMC standards of target export markets. The Desktop Power Adapter can complete pre-testing in advance to eliminate interference hidden dangers and avoid terminal product certification failure.

3. The Desktop Power Adapter supports customized shielded cables, which further weakens noise coupling in long-distance wiring scenarios and ensures signal stability of long-line power supply.

4. The shell, plug and silk screen logo of the Desktop Power Adapter can be customized to match the appearance design of terminal equipment, realize overall visual unity of products and enhance brand texture.

Conclusion

With ultra-low ripple and excellent EMC performance, the Desktop Power Adapter perfectly adapts to exported equipment such as audio-video products and precision medical peripherals.

Sen Shu Qiang provides EMC test reports, noise optimization customization and sample commissioning services to help precision electronic equipment pass overseas certifications smoothly and steadily expand international markets.

Sources

1.IEC 62368-1:2018

2.(EU) 2019/1782

3.EN 55032:2015