Intel IXF1104 - Manual (Page 63)

Intel
®
IXF1104 4-Port Gigabit Ethernet Media Access Controller
63 Datasheet
Document Number: 278757
Revision Number: 009
Revision Date: 27-Oct-2005
4.7 Power Supply Sequencing
Follow the power-up and power-down sequences described in this section to ensure correct
IXF1104 MAC operation. The sequence described in
Section 4.7 covers all IXF1104 MAC digital
and analog supplies.
Caution: Failure to follow the sequence described in this section might damage the IXF1104 MAC.
4.7.1 Power-Up Sequence
Ensure that the 1.8 V analog and digital supplies are applied and stable prior to application of the
2.5 V analog and digital supplies.
4.7.2 Power-Down Sequence
Remove the 2.5 V supplies prior to removing the 1.8 V power supplies (the reverse of the power-up
sequence).
Caution: Damage can occur to the ESD structures within the analog I/Os if the 2.5 V digital and analog
supplies exceed the 1.8 V digital and analog supplies by more than 2.0 V during power-up or
power-down.
Figure 5 and Table 19 provide the IXF1104 MAC power supply sequencing.
Figure 5. Power Supply Sequencing
Time
t=0
1.8 V Supplies Stable 2.5 V Supplies Stable
Sys_Res
Apply VDD, AVDD1P8_1, and
AVDD1P8_2 Apply VDD4, VDD5,
AVDD2P5_1 and AVDD2P5_2
NOTE: The 3.3 V supply (VDD2 and VDD3) can be applied at any point during this sequence.