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ADC3562: Unused REFBUF and VCOM pins

Part Number: ADC3562

Tool/software:

Hello team,

What should I do if I don't use REFBUF and VCOM pins?

Can I leave them floating?

Best Regards,
Kei Kuwahara

  • Hi Kei-san,

    What is customer wanting to use as voltage reference? See table below. Pulling this pin high through a 10k pullup resistor to 1.8V will use the external 1.6V voltage reference that is supplied through the VREF pin. If wanting to use a 1.2V reference, then supply the 1.2V reference to this REFBUF pin. If wanting to use internal reference, then supply a 0.6V signal or pulldown to GND through a 10k for differential clock and single ended clock options, respectively.

    If the customer is using multiple of this chip in a larger system and wants to ensure the reference voltage is common across them all, then using one of the external reference options will ensure this. If this is a single ADC3562 on the customer board then the internal reference is easiest and requires no external 1.6V or 1.2V precision reference.

    I am guessing VCOM is a typo for VCM output pin? If so, I recommend connecting a 0.1uF capacitor to GND if not driving a common mode input of an upstream differential amplifier.

    Thanks, Chase

  • Hi Chase-san,

    Thank you for the detailed answer!

    Sorry missed that from datasheet.

    Best Regards,
    Kei Kuwahara