ADRV9002 1.3V Rail Question

Hi,

I have a customer that is trying to combine the 1.3V ADRV9002 rail with DDR3L to limit number of regulators on the board. 

In trying to meet the min/max of the ADRV9002 and the DDR3L (taking into consideration the tolerance of the Vref and FB resistors), they are seeing that to set the voltage to a point that satisfies both the rail may be as high as 1.3325V and for margin they want to consider 1.35V. 

Datasheet shows 1.33V for operation and 1.5V for max.  In reality the 1.3325V is a worse case across temperature and tolerance so for most cases the voltage should be less than 1.33V.  But what is the performance or issue that may arise if it does go above 1.33V? 

Can you advise?

Thanks,

Anita

  • 0
    •  Analog Employees 
    on Jul 28, 2021 10:52 AM

    Hello Anita,

    Depending on how the power supply lines are all connected and which LDOs are used in which configuration, the 1.3V line is used to produce the 1.0V supply, so the 1.3 line ends up affecting the PLLs and the RF signal chains. If the 1.3V line is unstable or too high / low you may see inaccurate frequency locking, spurious content in the input / output spectrums, things like that.

    I hope this helps you support your customer!

    Best Regards,
    Oisín.

  • +1
    •  Analog Employees 
    on Aug 27, 2021 1:11 PM

    Hi Anita, 

    Following on from Oisín's response, we will not guarantee any specs to the customer since the supply would be out of the design/characterization range.

    There could be damage to the part in the long term since it was not designed for reliability at any voltages higher than what we advertise in the datasheet.

    Regards