ISO3082: The ISO3082 will burn accident in the following circuit.

Kevin Chen81

Intellectual 340 points

Part Number: ISO3082

Please check the peripheral circuit configuration of ISO3082. The ISO3082 will burn accident in the following circuit.

could you please help me to find out the mistakes?

Many Thanks.

Kevin Chen

2019.03.15

over 5 years ago

0 Lucas Schulte9 over 5 years ago

TI__Expert 6955 points

Kevin,

GND2 needs to be the same for U10 and U11. The schematic shows GND2 being different in the highlighted areas. Also, it appears that RS485A and RS485B are being shorted together through the highlighted diodes. What is the purpose of these diodes?

Respectfully,

Lucas

0 Kevin Chen81 over 5 years ago in reply to Lucas Schulte9

Intellectual 340 points

Hi Lucas,

Our customer confirms that the two GND are connected together. And The circuit of BAV99 is connected as follows.

Please help us to check the principle of the circuit again to confirm if there is any problem.

Many thanks.

Kevin Chen

2019.03.25

0 Lucas Schulte9 over 5 years ago in reply to Kevin Chen81

TI__Expert 6955 points

Kevin,

Does the ISO3082 get hot immediately after powering on? Is it both ICs that get hot? Was there some sort of event that led to the ISO3082 getting hot like surge testing? Any details you can provide on the circumstances surrounding the issue will help me greatly.

Respectfully,

Lucas

0 Kevin Chen81 over 5 years ago in reply to Lucas Schulte9

Intellectual 340 points

Hi Lucas,

Normally, the ISO3082 chip is not feverish. The burnout of ISO3082 is a problem that occurs when users use it. It is uncertain whether it has been heated for a long time or whether it has been caused by some kind of voltage shock. At present, the probability of recurrence of fault problems is relatively low, and it is difficult to capture fault phenomena.

In the above circuit, if Z20 is broken down, will it be possible to damage the ISO3082 chip?

Kevin Chen

0 Lucas Schulte9 over 5 years ago in reply to Kevin Chen81

TI__Expert 6955 points

Kevin,

Has the customer tried removing Z20? If Z20 has failed, then it is very possible it has failed short. This would cause the bus lines to be shorted to each other.

Respectfully,

Lucas

0 Lucas Schulte9 over 5 years ago in reply to Lucas Schulte9

TI__Expert 6955 points

Kevin,

Unfortunately I will have to close the thread soon but feel free to open a new thread if the issue hasn't been resolved yet. Is there any feedback from the customer about removing Z20?

Respectfully,
Lucas

0 Lucas Schulte9 over 5 years ago in reply to Lucas Schulte9

TI__Expert 6955 points

Kevin,

Unfortunately I have to close the thread due to internal time limits. Please feel free to start a new thread if this issue has not been resolved.

Respectfully,
Lucas

Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

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ISO3082: The ISO3082 will burn accident in the following circuit.