SUSPND

XTAL1

XTAL2

RESET

TSTPLL/48MCLK

EEDATA/GANGED

EECLK

10, 14, 18, 22

8

5

6

26

4

29

30

27

32

1

2

24

23

20

19

16

15

12

11

9, 13, 17, 21

BUSPWR

OVRCUR1

OVRCUR4

–

PWRON1

PWRON4

–

EXTMEM

DP0

DP4

DP3

DP2

DP1

DM0

DM4

DM3

DM2

DM1

USB

Transceiver

Suspend/Resume

Logic and

Frame Timer

HUB Repeater

SIE

USB

Transceiver

USB

Transceiver

USB

Transceiver

USB

Transceiver

OSC/PLL

Serial

EEPROM

Interface

Hub/Device

Command

Decoder

Port 4

Logic

Port 3

Logic

Port 2

Logic

Port 1

Logic

SIE Interface

Logic

Hub

Power

Logic

9

TUSB2046B, TUSB2046BI

www.ti.com

SLLS413K – FEBRUARY 2000 – REVISED JANUARY 2016

Product Folder Links: TUSB2046B TUSB2046BI

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Copyright © 2000–2016, Texas Instruments Incorporated

8.2 Functional Block Diagram

8.3 Feature Description

8.3.1 USB Power Management

External power-management devices, such as the TPS2044, are required to control the 5-V source to the

downstream ports according to the corresponding values of the PWRON pin. Upon detecting any overcurrent

conditions, the power-management device sets the corresponding OVRCUR pin of the TUSB2046B to a logic

low. If GANGED is high, all PWRON outputs switch together and if any OVRCUR is activated, all ports transition

to the power-off state. If GANGED is low, the PWRON outputs and OVRCUR inputs operate on a per-port basis.

Both bus-powered and self-powered hubs require overcurrent protection for all downstream ports. The two types

of protection are individual-port management (individual-port basis) or ganged-port management (multiple-port

basis). Individual-port management requires power-management devices for each individual downstream port,

but adds robustness to the USB system because, in the event of an overcurrent condition, the USB host only

powers down the port that has the condition. The ganged configuration uses fewer power-management devices

and thus has lower system costs, but in the event of an overcurrent condition on any of the downstream ports, all

the ganged ports are disabled by the USB host.