DAC80508: Enabling external VREF before DAC configuration results in high current at Vdd

Dear Team,

I'm using the DAC with an external 5V reference (REF5050) which is directly connected with REF-Pin of the DAC80508.

When starting up I first power the DAC with 3.3V (VIO) and 5V (VDD). This means that the internal reference is active and 2.5V can be seen at REF. As I power the external reference later, I can see that the REF-Pin tries to power the REF5050 and 10mA is drained via VDD.

For the case that I have the DAC and REF5050 at startup active, then I see that the ext reference tries to push out 5V resulting in running 20mA into the REF5050.

So from my point of view I have two approaches:

1) Power on DAC -> configure VREF to external mode -> Enable REF5050 via analog-switch (as no enable pin is present.)

2) Power on DAC and REF5050 -> configure VREF to external mode

For case 1) I drain 10mA from REF-Pin for some seconds or even longer

For case 2) 20mA are running through REF5050 and into REF-Pin (also 8mA are drained by VDD)  for some seconds or even longer

For both cases I see stress on either the DAC REF-pin or DAC REF-Pin and REF5050. From implementation point of view case 2) is less complex.

Finally my question:
Can any of both ICs be damaged by stress through current, if implementation case 2) is used?

Thanks for your help in advance