The PIC18F56Q24 features one MVIO domain powered by VDDIO2. Pins
PC3 through PC6 and the pins in PORTD are powered through VDDIO2. The I/O pins
connected to the MVIO feature are powered only by the additional VDDIO2 pin.
If no power is supplied to this power pin, the associated I/O pins will not function.
VCC_TARGET supplies VDDIO2 by default. Removing the 0Ω resistor R105 disconnects the default power connection. After the removal, an external
power supply can power the MVIO pins through the associated 1x2-100mil footprint (J107). The
block diagram below details the connections to the VDDIO2 power domain.
Tip: The VDDIO2 supply voltage can go below the
device’s minimum VDD of 1.8V, with a minimum voltage of 1.62V.
Warning: Before any hardware
modifications, ensure the board is disconnected from the USB or external
power.
Disconnecting VDDIO2:
Disconnect VDDIO2 from
VCC_TARGET by removing resistor R105
Connect a new power supply to
VDDIO2 and ground at J112
Warning: J112 does not have reverse
polarity protection. Applying voltage to the wrong pin may cause permanent damage to the
board.
Warning: Applying an external voltage
to VDDIO2 without removing the resistor may cause permanent damage to the
board!
The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.
