TUSB2046B, TUSB2046BI

4PORT HUB FOR THE UNIVERSAL SERIAL BUS

WITH OPTIONAL SERIAL EEPROM INTERFACE

SLLS413B − FEBRUARY 2000 − REVISED DECEMBER 2004

16

POST OFFICE BOX 655303

APPLICATION INFORMATION

self-powered hub, ganged-port power management (continued)

6-MHz Clock

Signal

† TPS2044, TPS2042, and SN75240 are Texas Instruments devices.

The TPS2024 can be substituted for the TPS2044.

‡ 120 µF per hub is the minimum required per the USB specification, version 1.1. However, TI recommends a 100-µF, low ESR, tantalum capacitor

per port for immunity to voltage droop.

§ LDO is a 5-V-to-3.3-V voltage regulator

DP1

DM1

DP2

DM2

PWRON1

PWRON2

PWRON3

PWRON4

OVRCUR1

OVRCUR2

OVRCUR3

OVRCUR4

GND

XTAL1

XTAL2

EXTMEM

RESET

TPS2044†

IN1

EN1

OUT1

D +

D −

5 V

GND

D +

D −

5 V

Downstream

Ports

OC1

TUSB2046B

DP3

DM3

DP4

DM4

SN75240†

A

B

C

D

100

GND

100

DP0

DM0

VCC

5 V

3.3 V

GND

D +

D −

Upstream

Port

SN75240†

A

B

5 V

GND

C

D

4.7

µF

0.1

µF

4.7

µF

Ferrite Beads

5 V Board Power

Supply

Ferrite Beads

0.1

µF

D +

D −

5 V

GND

D +

D −

5 V

GND

100

Ferrite Beads

SN75240†

A

B

C

D

100

BUSPWR

3.3 V

Ferrite Beads

EEDATA/GANGED

System

Power-On Reset

EN2

EN3

EN4

OC2

OC3

OC4

OUT2

OUT3

OUT4

IN2

3.3 V

1.5 k

Ω

3.3 V

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

¶ All USB DP, DM signal pairs require series resistors of approximately 27 Ω to ensure proper termination. An optional filter capacitor of about

22 pF is recommended for EMI suppression. This capacitor, if used, must be placed between the hub terminal and the series resistor, as per

section 7.1.6 of the USB specification.

¶

Figure 12. TUSB2046B Self-Powered Hub, Ganged-Port Power-Management Application