EVB8740/EVB8741 Evaluation Board User Manual
SMSC EVB8740/EVB8741
3
Revision 1.0 (04-29-13)
USER MANUAL
2 Board Details
This section includes the following EVB8740/EVB8741 board details:
2.1
Power
2.1.1
+5V Power
Power is normally supplied to the EVB8740/EVB8741’s +3.3V regulator externally via the +5V power
pins of the MII connector. If desired, the EVB8740/EVB8741 can be powered w5V present on
the MII connector by sup5V to the TP2 (red) test point with ground connected to the TP4
(black) test point.
Note:
Before connecting an external power supply to TP2, ensure power is not present on the MII
connector’s +5V pins. Conn5V simultaneously via the MII connector and TP2 may
result in permanent damage to the board.
2.1.2
VDDIO Power
The LAN8740A/LAN8741A’s VDDIO power may be supplied at a voltage other than +3.3V by
depopulating resistor R12 and sup1.6V to +3.6V externally via test point TP5 (purple), with
ground connected to the TP4 (black) test point.
Note:
Before connecting an external power supply to TP5, ensure that resistor R12 has been
removed. Connecting an external power supply to TP5 while resistor R12 is populated may
result in permanent damage to the board.
2.1.3
+1.2V Power
The LAN8740A/LAN8741A’s in1.2V regulator can be optionally disabled. Refer to
"In1.2V Regulator Configuration (REGOFF)," on page 6
for additional information.
