TUSB2046B, TUSB2046BI

4PORT HUB FOR THE UNIVERSAL SERIAL BUS

WITH OPTIONAL SERIAL EEPROM INTERFACE

SLLS413B − FEBRUARY 2000 − REVISED DECEMBER 2004

18

POST OFFICE BOX 655303

APPLICATION INFORMATION

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

6-MHz Clock

Signal

BUSPWR

DP1

DM1

DP2

DM2

DP3

DM3

DP4

PWRON1

PWRON2

PWRON3

PWRON4

OVRCUR1

OVRCUR2

OVRCUR3

OVRCUR4

DM4

DP0

DM0

VCC

GND

XTAL1

XTAL2

EXTMEM

RESET

5 V

3.3 V

GND

D +

D −

Upstream

Port

SN75240†

EN1

OC1

D +

D −

5 V

GND

D +

D −

5 V

D +

D −

5 V

D +

D −

5 V

Downstream

Ports

5-V Board Power

Supply

TUSB2046B

TPS2044†

A

B

C

D

100

SN75240†

A

B

C

D

GND

GND

GND

100

100

100

† TPS2042 and SN75240 are Texas Instruments devices. Two TPS2042 devices 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.

SN75240†

A

B

5 V

GND

C

D

4.7

µF

0.1

µF

4.7

µF

EN2

EN3

EN4

OC2

OC3

OC4

OUT4

OUT3

OUT2

OUT1

EEDATA/GANGED

System

Power-On Reset

IN1

0.1

µF

IN2

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

15 k

Ω

15 k

Ω

15 k

Ω

15 k

Ω

3.3 V

1.5 k

Ω

3.3 V

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 13. TUSB2046B Self-Powered Hub, Individual-Port Power-Management Application