[ADV7280] About the register "LL_NSTD"

Hi,

   Please let us know, whether you are using Consumer or Automotive version of ADV7280-M ?.

      -- The consumer version ADV7280KCPZ-M is rated to -10 'C.

      -- The automotive version ADV7280WBCPZ-M is rated to -40 'C.

  If it is consumer version, then the part is not expected to work below -10'C according to the ordering guide.

Thanks,

Poornima

Hello, thank you for your answer.

We are using  Automotive version of ADV7280-M.

Best regards,

Shioya

Hi,

  Could you please refer the addressed query at (+) adv7280m doesn't work at the temperature of -15 centigrade - Q&A - Video - EngineerZone (analog.com), Here expert has given some suggestion about when using the part in low temperature.

   If possible, Please use the ELPF capacitors with COG (NPO) materials and this material especially used for extended temp range products like automotive products Since X7R has very poor temp-coefficient. 

  Please note, Due to temperature co-efficient of X7R material, a 10nF might only be 5nF which would put the PLL filter out of specification (PLL filter is sensitive to this). C0G material has a much better temperature co-efficient.

Thanks,

Poornima

I wanted to thank you for the great advice.

Hello

As a result of reflecting the advice, "address 0x12: LL_NSTD non-standard line length" was resolved.

However, I have found that the adv7280m does not work at temperatures below -20 degrees Celsius.

Are there any other measures to take?

Best regards,

Shioya

Hi,

 Please ensure with below package description,

      1. The consumer version of the ADV7280-M (ADV7280KCPZ-M) is only rated to -10 'C.
      2. The automotive and industrial versions of the ADV7280-M (ADV7280WBCPZ-M and ADV7280BCPZ-M) are rated to -40 'C.

Hello, thank you for your answer.

We are using  Automotive version of ADV7280-M.

Best regards,

Shioya

Hi,

   Could you please ensure with below things,

1) Please check power supplies and power filters are stable at -20C?

2) Is your crystal, 28.6363 the correct frequency at -20C?

3) What materials are the ELPF capacitors made of (X7R)?  Try C0G (NPO) if possible.

Please note " Keep in mind capacitors can have poor temperature coefficients at low temperature.  In general, C0G or NPO materials are used for the load caps on the crystal which is good.  However, the caps are often X7R material which have very poor coefficients often pushing the caps out of acceptable range at low temps.

PVDD rail needs ferrite beaded isolation by itself. PVDD needs to be very clean for stability output.

Also ensure with "ADI Required Settings" and these are the ones which is found to work over the tested range of voltage/temperature/inputs

Thanks,

Poornima

Hi,

   Could you please ensure with below things,

1) Please check power supplies and power filters are stable at -20C?

2) Is your crystal, 28.6363 the correct frequency at -20C?

3) What materials are the ELPF capacitors made of (X7R)?  Try C0G (NPO) if possible.

Please note " Keep in mind capacitors can have poor temperature coefficients at low temperature.  In general, C0G or NPO materials are used for the load caps on the crystal which is good.  However, the caps are often X7R material which have very poor coefficients often pushing the caps out of acceptable range at low temps.

PVDD rail needs ferrite beaded isolation by itself. PVDD needs to be very clean for stability output.

Also ensure with "ADI Required Settings" and these are the ones which is found to work over the tested range of voltage/temperature/inputs

Thanks,

Poornima

Hello, thank you for your answer.

Please confirm my answer as indicated below.

>1) Please check power supplies and power filters are stable at -20C?

      Power supplies and power filters are stable at -20C.

>2) Is your crystal, 28.6363 the correct frequency at -20C?

      The crystal oscillates at 28.63636 MHz at -20°C.

>3) What materials are the ELPF capacitors made of (X7R)?  Try C0G (NPO) if possible.

      CH capacitors are used.

>PVDD rail needs ferrite beaded isolation by itself. PVDD needs to be very clean for stability output.

      Ferrite beads are used before the PVDD input.

>Also ensure with "ADI Required Settings" and these are the ones which is found to work over the tested range of >voltage/temperature/inputs

  Does "ADI Required Settings" have the same meaning as IC default settings?
  I could not find the words "ADI Required Settings" in the ADV7280 datasheet.

Hi,

  Please find the below comment,

  Does "ADI Required Settings" have the same meaning as IC default settings ?

    YES, this is IC default settings and these writes are non-user adjustments.

"ADI recommended Write" - if those writes are not included, the part would not work reliably (unless those values are default anyway). Those registers are generally internal settings that let us handle process variation which is why they are determined during characterization. The settings that show up as "ADI Recommended Settings" are the values that work reliably across voltage and temperature. They really should be called "ADI Required setting.

  I could not find the words "ADI Required Settings" in the ADV7280 datasheet.

          We can find the ADI required settings in the ADV7280 script at 4774.ADV7280_CUST-VER.4.5.txt.zip

Thanks,

Poornima