Integrated USB 2.0 Compatible 4-Port Hub

 

 

 

 

Datasheet

 

 

Table 4.3 Miscellaneous Pins (continued)

 

 

 

 

 

NAME

SYMBOL

 

TYPE

FUNCTION

 

 

 

 

 

RESET Input

RESET_N

 

IS

This active low signal is used by the system to reset the

 

 

 

 

chip. The minimum active low pulse is 1us.

 

 

 

 

 

Self-Power /

SELF_PWR

 

I

Detects availability of local self-power source.

Bus-Power

 

 

 

Low = Self/local power source is NOT available (i.e., Hub

Detect

 

 

 

gets all power from Upstream USB VBus).

 

 

 

 

High = Self/local power source is available.

 

 

 

 

 

TEST Pins

TEST[1:0]

 

IPD

Used for testing the chip. User must treat as a no-

 

 

 

 

connect or connect to ground.

 

 

 

 

 

Analog Test

ATEST/

 

AIO

This signal is used for testing the analog section of the

&

REG_EN

 

 

chip, and to enable or disable the internal 1.8v regulator.

Internal 1.8V

 

 

 

This pin must be connected to VDDA33 to enable the

voltage

 

 

 

 

 

 

internal 1.8V regulator, or to VSS to disable the internal

regulator

 

 

 

 

 

 

regulator.

enable

 

 

 

 

 

 

 

 

 

 

 

When the internal regulator is enabled, the 1.8V power

 

 

 

 

pins must be left unconnected, except for the required

 

 

 

 

bypass capacitors.When the PHY is in test mode, the

 

 

 

 

internal regulator is disabled and the ATEST pin

 

 

 

 

functions as a test pin.

 

 

 

 

 

 

 

Table 4.4 Power, Ground, and No Connect

 

 

 

 

 

NAME

SYMBOL

 

TYPE

FUNCTION

 

 

 

 

 

VDD1P8

VDD18

 

 

+1.8V core power.

 

 

 

 

If the internal regulator is enabled, then VDD18 pin 54

 

 

 

 

must have a 4.7μF (or greater) ±20% (ESR <0.1Ω)

 

 

 

 

capacitor to VSS

 

 

 

 

 

VDDAPLL3P3

VDDA33PLL

 

 

+3.3V Filtered analog power for the internal PLL

 

 

 

 

If the internal PLL 1.8V regulator is enabled, then this pin

 

 

 

 

acts as the regulator input

 

 

 

 

 

VDDAPLL1P8

VDDA18PLL

 

 

+1.8V Filtered analog power for internal PLL.

 

 

 

 

If the internal regulator is enabled, then this pin must

 

 

 

 

have a 4.7μF (or greater) ±20% (ESR <0.1Ω) capacitor

 

 

 

 

to VSS

 

 

 

 

 

VDDIO3P3

VDD33

 

 

+3.3V I/O power.

 

 

 

 

 

VDDA3P3

VDDA33

 

 

+3.3V Filtered analog power.

 

 

 

 

 

VSS

VSS

 

 

Ground.

 

 

 

 

 

Revision 2.3 (08-27-07)

14

SMSC USB2504/USB2504A

 

DATASHEET