ADS8689: REFIO or REFCAP for buffered voltage reference?

Tool/software:

Hello,

I would like to use the internal 4.096V reference on the ADS868X ADC for other circuitry on my board. I intend to use a op-amp buffer so I do not load the internal reference, as per section 7.3.7.1 of the datasheet (ADS868X), which states the following " The REFIO pin must not be used to drive external ac or dc loads because of limited current output capability. The REFIO pin can be used as a source if followed by a suitable op amp buffer (such as the OPA320). "

My question is, should I attach a op-amp unity gain buffer to the REFIO pin or the REFCAP pin?

Option 1:

• ADS8689 configured with internal 4.096V reference.
• REFIO pin -> decoupling capacitors -> opamp unity gain buffer -> voltage reference

Option 2:

• ADS8689 configured with internal 4.096V reference.
• REFCAP pin -> decoupling capacitors -> opamp unity gain buffer -> voltage reference

Thanks,

Dimitri