As testing, ADM3053 pin7 GND1 input impedance(about 20ohm) is different than other GND1 pin(about 2ohm).

When I let pin7 floating, the single noise is less then connected GND1.

Can you let me know why pin7 is different than other GND1 pin.

if I let pin7 floating, is it OK?


  • Hi Jackey,

    The reason for your different input impedance measurements is due to the bond out wires from the package pins to dice within the ADM3053 package.

    Pin 7 needs to be connected to ground 1 (GND 1).

    Please see the ADM3053 data sheet page 15, Figure 28 which shows a typical ground fill for Pin 7.

    Best Regards,