Opal Kelly issues this PCN to existing customers of the listed product(s) to inform them of changes and/or updates that may affect current inventory or current and future applications of the product.
14 June 2023
The following items are affected by this PCN:
Customers utilizing LVCMOS or LVDS I/O standards on bank 64 are generally unaffected by this PCN.
PCB revisions AXX and later which are manufactured with the
C1 component installed are affected by this PCN. Revisions AXX manufactured without the
C1 component installed are not affected by this change. The PCB revision is indicated in silkscreen in the location shown below.
Revisions AXX without
C1 installed are not affected.
Revisions AXX and later, with
C1 installed are affected.
Reason for the Change
The reference voltage for Bank 64 is only required for certain not commonly used I/O standards. In most cases, a resistor or capacitor is not required on the Vref pin. However some I/O standards require the use of the internal reference voltage, which requires that a resistor be placed between the Vref pin and ground. In order to support the most possible I/O standards by default, a resistor can be placed from the Vref pin to ground.
Description of the Change
A 1K Ohm resistor is now being placed on the component designator C1. This allows for the internal voltage reference to be used on Bank 64.