LMK04816: Digital Output Values when Supplying with 5V

Devin Thompson

Part Number: LMK04816

Tool/software:

Hi,

We have a board using the LMK04816, and due to an error the chip was supplied with 5V instead of 3.3V. We have rectified the issue and will replace the chip itself but need to know if the digital outputs (pins 45-47) would have also tried to output at 5V. This would cause damage to other areas of the design that will need to be looked into. According to the datasheet, the high value on the digital output is VCC, but in this case, we are not confident on whether that value would have been 3.3V or 5V.

Thanks,

Devin

3 months ago

0 William Pfennigwerth 3 months ago

TI__Expert 8231 points

Devin,

Vcc is 3.3V as stated in section 6.3 of the datasheet.

Regards,

Will

0 Devin Thompson 3 months ago in reply to William Pfennigwerth

Prodigy 10 points

Will,

This does not answer my question. I understand the VCC is 3.3V. My issue is that I accidentally powered the chip with 5V and would like to know the ramifications of that on the rest of my board (mainly the digital outputs of the chip). We had some LMKs that were actually operating at the 5V and would like to know if the digital outputs would have tried to communicate at 5V or at 3.3V.

0 William Pfennigwerth 3 months ago in reply to Devin Thompson

TI__Expert 8231 points

Devin,

I apologize for misunderstanding your question. I have reached out to our design team to check on this for you. I will update you when I hear back.

Regards,

Will

0 William Pfennigwerth 3 months ago in reply to William Pfennigwerth

TI__Expert 8231 points

Devin,

Upon rereading your question. Pins 44-47 are inputs, not outputs. Therefore the Vcc spec on the datasheet is the maximum input voltage that the LMK04816 can accept. There is no output voltage from these pins. Is there a concern that your clock outputs could have been driven to 5V? If so what driver type were your outputs set to?

Regards,

Will

Clock & timing

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LMK04816: Digital Output Values when Supplying with 5V