Ω

Ω

1.5 kΩ

Ω

Ω

Ω

Ω

NOTES: A.

B.

C. LDO is a 5-V-to-3.3-V voltage regulator

D. All USB DP, DM signal pairs require series resistors of approximately 27

TPS2044, TPS2042, and SN75240 are Texas Instruments devices. Two TPS2042 devices can be substituted for the TPS2044.

The

outputs of the TPS204n are open drain. A 10-k pullup is recommended.

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

tantalum capacitor per port for immunity to voltage droop.

OCn

Ω

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.

SN75240

A

TPS2044

A

SN75240

A

3.3 V LDO

C

D

100 µF

B

100 µF

B

100 µF

B

100 µF

B

SN75240

A

TUSB2046B

TUSB2046BI

SLLS413I – FEBRUARY 2000 – REVISED SEPTEMBER 2013

www.ti.com

Self-Powered Hub, Individual-Port Power Management

In a self-powered configuration, the TUSB2046B can be implemented for individual-port power management

when used with the TPS2044, because it is capable of supplying 500 mA of current to each downstream port and

can provide current limiting on a per-port basis. When the hub detects a fault on a downstream port, power is

removed from only the port with the fault and the remaining ports continue to operate normally. Self-powered

hubs are required to implement overcurrent protection and report overcurrent conditions. The SN75240 transient

suppressors reduce inrush current and voltage spikes on the data lines.

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

16

Submit Documentation Feedback

Copyright © 2000–2013, Texas Instruments Incorporated

Product Folder Links: TUSB2046B TUSB2046BI