Ω

Ω

Ω

Ω

Ω

Ω

1.5 kΩ

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. The TPS2042 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

SN75240

A

SN75240

A

TPS2044

A

100 µF

B

100 µF

B

100 µF

B

3.3 V LDO

C

D

100 µF

B

TUSB2046B

TUSB2046BI

www.ti.com

SLLS413I – FEBRUARY 2000 – REVISED SEPTEMBER 2013

Self-Powered Hub, Ganged-Port Power Management

The TUSB2046B can also be implemented for ganged-port power management in a self-powered configuration.

The implementation is very similar to the bus-powered example with the exception that a self-powered port

supplies 500 mA of current to each downstream port. The overcurrent protection can be provided by a TPS2044

quad device or a TPS2024 single power switch.

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

Copyright © 2000–2013, Texas Instruments Incorporated

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Product Folder Links: TUSB2046B TUSB2046BI