Electromagnetic Compatibility (EMC) is a core requirement for the stable operation of electronic equipment, encompassing two bidirectional aspects: electromagnetic radiation and electromagnetic susceptibility. As the physical carrier of components, the design of the Printed Circuit Board (PCB) directly determines the lower limit of EMC performance. Unreasonable layer layouts, component placement, or grounding methods may lead to issues such as excessive radiation and signal interference, and even affect the equipment's certification results.

The Foundation of EMC Design: PCB Layer Layout

The layer structure of a PCB consists of power layers, ground layers, and signal layers. The selection of layers and their relative positions mark the starting point of EMC design. The core logic here is to reduce noise and minimize signal radiation through inter-layer coupling.

Component Layout for Reducing Radiation at the Source

Components act as either EMC noise sources or sensitive points. The core principle of this layout is to minimize current loops and isolate noise sources from sensitive components, thereby effectively reducing radiation.

1. "Miniaturization" of Noise Sources: High-speed switching components such as MOSFETs and switching power supply chips are major noise sources, and their package size directly affects radiation area. Heketai’s SOT-23 packaged MOSFETs and TO-252 packaged MOSFETs enable high-density layout through small packages, shortening signal trace length and reducing current loop area by over 30%—effectively lowering radiation intensity.
2. "Isolation" of Sensitive Components: Sensitive components like sensors and ADCs need to be kept away from noise sources. Heketai’s small-sized 0402 chip resistors allow physical isolation between sensitive components and noise sources in limited space, reducing radiation interference.
3. Consistency of Component Parameters: Parameter fluctuations in resistors and MOSFETs can cause unstable ground loop impedance, leading to residual noise. Heketai’s chip resistors have a tolerance of ±1%, and the on-resistance fluctuation of its MOSFETs is less than 5%. Such high parameter consistency ensures stable ground loop impedance, enabling smooth discharge of noise to the ground plane.

Grounding Design: The "Discharge Channel" for Noise

Grounding is the final critical step in EMC design. A low-impedance ground loop can quickly divert noise, preventing it from reflecting or radiating in the circuit. Key requirements for grounding design are as follows:

1. Combination of Single-Point and Multi-Point Grounding: Single-point grounding is used for low-frequency circuits to avoid ground loop current interference; multi-point grounding is adopted for high-frequency circuits to reduce ground impedance.
2. Integrity of the Ground Plane: Avoid arbitrary slots on the ground plane and maintain its continuity to ensure noise is discharged to the ground via the shortest path.
3. "Low-Impedance Grounding" for Components: Heketai’s SOT-23 packaged TVS diodes can be mounted next to interface circuits. Through low-impedance grounding, they quickly absorb external conducted noise, enhancing the equipment’s electromagnetic susceptibility performance.

Conclusion

EMC is not an abstract concept but a precise design based on electromagnetic principles. Rational PCB layer layout, component placement, and grounding methods can reduce noise at the source; meanwhile, Heketai’s small-packaged, high-consistency, and low-noise components are key tools to implement these principles. Whether for industrial control, automotive electronics, or consumer devices, Heketai can provide adaptive component solutions to help engineers solve EMC issues and achieve stable product certification.

Company Introduction

Founded in 1992, Heketai is a high-tech enterprise specializing in electronic components, integrating R&D, design, production, and sales. It is also recognized as a "Specialized, Refined, Differential, and Innovative" enterprise. We focus on providing cost-effective component supply and customization services to meet the R&D needs of enterprises.

• Product Range: Covers semiconductor packaging materials, passive components (resistors/capacitors/inductors), as well as active components including MOSFETs, TVS diodes, Schottky diodes, Zener diodes, fast recovery diodes, bridge rectifiers, diodes, transistors, power devices, and power management ICs. We offer one-stop procurement for all R&D and production requirements.
• Two Smart Manufacturing Centers: Our South China (Huizhou, 75,000 m²) and Southwest (Nanchong, 35,000 m²) manufacturing centers are equipped with over 3,000 advanced devices and testing instruments. In 2024, we added 3 new semiconductor material subsidiaries to control production capacity and delivery efficiency from the source.
• Packaging and Testing OEM Services: We support sample customization and small-batch trial production. With over 100 patents and certification systems (ISO 9001, IATF 16949), we ensure "quality first" runs through every stage from R&D to delivery.

Adhering to the core values of "Customer-Centric, Innovation-Driven," Heketai is committed to providing stable and reliable components for enterprises.

(Note: For sample requests, solution consulting, or small-batch procurement ↓)

Contact Heketai via QR Code Scan

• Sales Hotline: 18823438533 (WeChat ID: Same as the phone number)
• Company Tel: 0755-82565333
• Email: hkt@heketai.com
• Marketing Center: 8th Floor, Building 7, Kangli City, Longgang District, Shenzhen City, Guangdong Province, China
• Manufacturing Centers:

1. 183B, Puxinhu Commercial Street, Tangxia Town, Dongguan City, Guangdong Province, China
2. Buildings 17 & 18, Science and Innovation Center, High-Tech Industrial Development Zone, Nanchong City, Sichuan Province, China