Routing a Power Inverter Design Guidelines
前言
客戶在馬達控制設計上常常會有layout上問題，但這邊很多是個架Know How，這邊ST提供重點關鍵設計指引避免在馬達控制上設計踩坑，最後導致ADC回授電路雜訊過多干擾實際馬達控制，另外也提供MOS設計規範指引讓客戶指引可以知道後續設計要點
Circuit loops Guidelines
基本上最重要一個要點就是避免大區域Loops設計(Avoid big area loops as much as possible!)
- Loops on the PCB are acting as coils
- The bigger loop area, the bigger issue
- Circuit with bigger area loop:
- Generates noise (e. g. switching of the transistors)
- Absorb noise (e. g. shunt signal feedback)
- Focus on complete loop: from source to load and
back to the source - Keep the area of the loops as small as possible!
Good component placement is the key
- By optimal components placement the routing
- can be easier
- Study the schematic first and decide what blocks
should be close to each other - There is no ideal placement!
Always compromise between general rules,
specifics of the inverter, manufacturing limits, etc.
連接方式會建議使用 Kelvin connection/Star Connection
範例
Current loop area is minimized and there are no sensitive circuits inside it
GND設計上會建議分開數位GND還有Power GND
其他MOS等設計可以參考下面文件Power MOSFETs: best choice guide for VRM applications