LAN7500 datasheet(48/58 Pages) MICROCHIP

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Hi-Speed USB 2.0 to 10/100/1000 Ethernet Controller

Datasheet

DS00001734A-page 48

 2014 Microchip Technology Inc

7.5.2

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 7.15.



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 operational limits), a power-on reset must be executed once all power supplies reach

operational levels. Refer to Section 7.5.3, "Power-On Reset Timing," on page 49 for power-on reset

requirements.



With the exception of VBUS_DET, do not drive input signals without power supplied to the device.

Note: Violation of these specifications may damage the device.

Note: The VDDVARIO power supply can be run at 2.5V or 3.3V.

Note: The magnetics power supply can be run at 2.5V or 3.3V.

Figure 7.2 Power Sequence Timing

Table 7.15 Power Sequence Timing Values

SYMBOL

DESCRIPTION

MIN

TYP

MAX

UNITS

tpon

Power supply turn on time

LAN7500 Datasheet(PDF) 48 Page - Microchip Technology