This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMK01010: at low temperature, LVDS output fails to function when set to low frequency

Part Number: LMK01010

Dear TI support,

we're currently using the LMK01010 in one of our audio products to drive audio codec clocks (due to its very good jitter performance).

We've however experienced a very strange issue when cooling the chip down to a low temperature. If the ambient temperature is close to or below 0 degrees centigrade, the chip's LVDS output does not function when configured with low output frequency setting (192kHz) however it functions properly with higher frequency setting (e.g. ~12MHz), input frequency is ~24MHz. LVDS output is AC coupled via 1uF capacitors, terminated with 100ohm. We tried disconnecting the whole bus of LVDS receivers from the output and only test the output itself (terminated with 100ohm and AC coupled via 1uF capacitors), nothing changed, it did not function at all when chip is cooled down (there are only short low voltage 192kHz timed spikes at the output). When however the VBOOST bit is set to 1, the outputs start to function properly even at low temp.

Can you please clarify what is going on with the chip when used in low-temp conditions with VBOOST=0 ?

Have you ever experienced such anomaly ? Is VBOOST=1 going to make the chip function properly under any ambient temp within the operating temp range ?

We've tested several LMK01010 chips from few different manufacturing batches (bought from different vendors) with the same results.

Thanks for any info provided.

Best Regards,

Otto Zeleznik

  • Hi Otto,

    Thanks for bringing this issue to our attention. I will check with the backend team on this issue and get back to you.

    Please let us know if setting VBOOST = 1 resolves the cold temp issue you have observed.

    Kind regards,