ISO3086: Output ripple at low temperature

Kenji Ohno1

Genius 5095 points

Part Number: ISO3086

Hi Team,

Please cooperate in investigating the cause.

Although the input waveform is constant, output ripple occurs at lower temperatures.

The ripple is almost invisible at room temperature, but the output ripple increases at -5℃ → -10℃ → -20℃.

Let me know what causes.

Best Regards,

Kenji

over 6 years ago

0 Lucas Schulte9 over 6 years ago

TI__Expert 6955 points

Kenji,

I'm sorry to hear about this problem however I will need much more information to be able to help. What do you man by output ripple? Are you referring to something on the bus lines? Would you be able to provide scope shots of this ripple? Can you provide a schematic? I need to know if there are any external components on the bus lines.

Respectfully,

Lucas Schulte

0 Kenji Ohno1 over 6 years ago in reply to Lucas Schulte9

Genius 5095 points

Hi Lucas,

Thank you for your reply.

But this problem is happening to my customers.

I have waveform information, but if you provide it, let me use a private message.

The input is 3V, the output is about 4V, and the ripple at -20℃ is about 1V.

Best Regards,

Kenji

0 Lucas Schulte9 over 6 years ago in reply to Kenji Ohno1

TI__Expert 6955 points

Kenji,

Yes you can send me the waveforms to my email and we can continue the discussion with email as well. However, I will still need answers to my other questions. Also I will need know what you mean by input and output for this device.

Respectfully,

Lucas Schulte

0 Lucas Schulte9 over 6 years ago in reply to Lucas Schulte9

TI__Expert 6955 points

FYI this issue was taken to PM. The issue seems to be that the power supply has significant ripple which causing the ripple to appear on the bus.

Respectfully,

Lucas

0 Lucas Schulte9 over 6 years ago in reply to Lucas Schulte9

TI__Expert 6955 points

FYI this issue was resolved offline. The source of the issue was severe ripple on the Vcc rail that occurred during cold temperature. Ripple from Vcc can easily appear on the bus lines of differential transceivers.

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ISO3086: Output ripple at low temperature