Design Review Summary Example

The following is one of several summaries provided to the customer who had asked us to review a power circuit that had just been designed. The customer needed immediate feedback and agreed to provide the summaries as each section was reviewed, allowing the customer to make changes in a rapid iterative process. Using e-mail, a record of the summaries was kept, including replies related to the summary.

Rotating MOSFETs

Title: Rotating MOSFETs (Q38 & Q39, etc.)
Category: Routing Optimization & Noise
Summary Notes:

• Rotating switching MOSFETs (Q38 & Q39, etc.) by 180 degrees as a pair places gates on the right near U33.
  

• Switching junctions closer to inductor L17. (Smaller switching node reduces E field EMI.)
  

• Other fuses, caps, etc., should also switch south-north sides of the L17 inductor to minimize switching current paths.
  

• Since the opening exists under the inductor, you can't route there. Minimize & Balance switching current paths.
  

• Isolate non-switching circuitry.
  

Recommendations:

• Minimize Switching voltage node size & coupling
  

• Minimize Switching current loop area
  

• Maximize isolation of switching nets to other nets.
  

Additional Details:
Applies by analogy to the other 5 converters as well.

• A report consisting of the correspondences and any final recommendations before parting ways.
  

• A log of the hours and what was done during those hours.
  

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