LAN8810 Datasheet, PDF (66/83 Pages) Microchip Technology – GMII 10/100/1000 Ethernet Transceiver

LAN8810/LAN8810I
5.5.2 POWER SEQUENCE TIMING
Power supplies must adhere to the following rules:
• All power supplies of the same voltage must be powered up/down together.
• There is no power-up sequencing requirement, however all power supplies must reach operational levels within
the time periods specified in Table 5-11.
• There is no power-down sequencing or timing requirement, however the device must not be powered for an
extended period of time without all supplies at operational levels.
• Following initial power-on, or if a power supply brownout occurs (i.e., one or more supplies drops below opera-
tional limits), a power-on reset must be executed once all power supplies reach operational levels. Refer to Sec-
tion 5.5.3, "Power-On Hardware Reset Timing," on page 67 for power-on reset requirements.
• Do not drive input signals without power supplied to the device.
Note: Violation of these specifications may damage the device.
FIGURE 5-2:
POWER SEQUENCE TIMING
t_pon
All 3.3V Power
Supply Pins
All 2.5V Power
Supply Pins
All 1.2V Power
Supply Pins
TABLE 5-11: POWER SEQUENCE TIMING VALUES
Symbol
t_pon
Description
Power supply turn on time
Note 1: The VDDVARIO power supply can be run at 2.5V or 3.3V.
2: The magnetics power supply can be run at 2.5V or 3.3V.
Min
Typ
Max
Units
0
25
mS
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DS00001870B-page 66