88e3015 Marvell Semiconductor, Inc., 88e3015 Datasheet - Page 35

• Manufacturer Part Number: 88e3015
• Description: Integrated 10/100 Fast Ethernet Transceiver
• Manufacturer: Marvell Semiconductor, Inc.

If the 1.2V regulator is not used, AVDDR must still be tied to 2.5V.
2.5.4 AVDDX
AVDDX is used as the 3.3V supply to the external regulator that generates the 2.5V supply.
AVDDX must be supplied externally. Note that this supply must be the same voltage as AVDDC.
If the 2.5V regulator is not used, then the CTRL25 pin should be left floating. In this particular case when the 2.5V
regulator is not used, the AVDDX pin should be left floating.
2.5.5 DVDD
DVDD is used as the 1.2V digital supply.
DVDD can be supplied externally with 1.2V, or via the 1.2V regulator.
All DVDD pins should be shorted together. A decoupling capacitor should be attached to pin 11 of the 88E3015
device and pin 13 of the 88E3018 device.
2.5.6 VDDO
VDDO supplies the non-MAC Interface digital I/O pins. The voltage range is 2.5V or 3.3V.
VDDO must be supplied externally. Do not use the 2.5V regulator to power VDDO.
2.5.7 VDDOR
VDDOR supplies the MAC Interface digital I/O pins. The voltage should be 2.5V or 3.3V.
VDDOR must be supplied externally. Do not use the 2.5V regulator to power VDDOR.
Three options are supported:
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•
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The VREF pin should be set to 0.5 x VDDOR for SSTL_2 behavior.
The VREF pin should be tied to VDDOR for LVCMOS behavior.
Note that 3.3V SSTL_2 is not supported.
Copyright © 2006 Marvell
October 26, 2006, Advance
2.5V LVCMOS
3.3V LVCMOS
2.5V SSTL_2
Note
Note
The CRS, COL, and RX_ER pins are on the VDDO supply.
The CRS, COL, and RX_ER pins are not on the VDDOR supply.
Document Classification: Proprietary Information
CONFIDENTIAL
Regulators and Power Supplies
Doc. No. MV-S103657-00, Rev. C
Page 35