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現在2149件がヒットしています。check
This is Sasaki in charge of power supply dock technology.
In this column, I would like to introduce some examples of problems related to power supplies that I encountered multiple times during various customer support sessions.
A customer asked us, ``During a comparative evaluation of the DC/DC converters of Company A and Company B, we encountered a problem where the power supply IC burned out, so we would like support.''
Pay close attention to evaluation methods
Click here for detailed symptoms
- The power supply ICs of Company A and Company B are pin-compatible products.
- Burnout occurred during prototype evaluation using a board designed by Company A in the past.
- Burnout does not occur when company A's power supply IC is used.
- Burnout occurs only when using a power supply IC from company B.
When I was verifying with the evaluation board, there was no problem with the power supply IC of company B, but when I started evaluating it with my company's board, it began to burn out.
Company B is attractive in terms of price, so I definitely want to use it...
Is that so. First, let's check the circuit diagram and layout diagram.
Check schematics and layout diagrams
The circuit diagram also has constants changed for Company B's power supply IC, and the layout seems to be no problem.
What is the cause...
Are you completely motionless?
No, it works normally at first, but it burns out during the evaluation.
Can you show us what you are actually evaluating?
When I moved to the laboratory and actually saw the evaluation method,
(I see. Is that what you mean!)
I know the reason.
It seems that there was a problem with the evaluation method.
Burnout occurred because the power supply IC was not mounted on the board and was connected to the board with lead wires.
e! Since it is easy to change the power supply IC, I used lead wires for evaluation.
With this method, a voltage exceeding the absolute maximum rating of the power supply IC may be generated due to the inductance component of the lead wire of the GND connection, and the power supply IC may burn out.
Is that so. . . Now, let's mount the power supply IC on the board and evaluate it!
After that, when we mounted the power supply IC on the board and performed the same evaluation, no burnout occurred.
Cause of power supply IC burnout
The power supply IC was not mounted on the board, but connected with lead wires.
The point of this time
When evaluating power supply ICs, be sure to mount them on the board!
(If you don't take the time to do this, it will cause problems like this one.)