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Design Reviews
Design reviews involve looking at different aspects
of the product to make sure the circuit not only functions correctly
but is also spec'd correctly. The best way of describing this
process is "another pair of eyes" with someone that has outside
experience. |
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Product Specification
- The product specification is key because that is what the
product is designed to meet
- Check to see all the appropriate specs are in the document
- Such as input voltage range, temperature range and standards like
IEC61000-4-X
- Verify that the spec levels are sufficient but reasonable
- For example IEC61000-4-X standards have multiple levels and which
level will depend on the end use
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Components
- Sufficient De-rating
- Not just voltage or temperature
- But making sure key specs are met on the device for the
application
- Like dV/dt rating of Mosfets for resonant power supply applications
- Check for obsolescence
- Aluminum Electrolytic Capacitor Life
- Known issues in the field
- See if there are substitutes that have better performance,
reliability or price
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Circuit Function
- Verify the circuit functions properly over the required
environment ranges
- Such as temperature, input voltage and output current
- Make sure the circuit is stable or how to test the
stability
- Check to see if there is sufficient protection like OV, UV,
OC for power supplies
- Make sure there are no thermal issues
- Suggest options for cost reduction or simpler circuit design
- Verify the magnetics designs such as transformers
- This involves verifying the transformer saturation current,
winding loss and core are within reason
- For custom magnetics verify the assembly drawing is
sufficient
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ESD, EMC
- Verify there is sufficient ESD protection
- Flag susceptible parts that may be ESD sensitive
- From an EMC emission aspect verify the circuit is
sufficiently quiet or flag potential issues
- From an EMC immunity aspect verify the circuit is
sufficiently protected from disturbances
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Layout
- Look over the layout to verify the trace spacings are
sufficient for the voltage
- Verify that the layout is sufficient for the circuit
function, ESD and EMC
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Manufacturability
- Verify the product can easily be manufactured and suggest
options for improvements
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