www.ti.com

DP1

DM1

DP2

DM2

DP3

DM3

DP4

PWRON1

OVRCUR1

PWRON2

OVRCUR2

DM4

DP0

DM0

XTAL1

XTAL2

OCSOFF

SN75240

D +

D −

5 V

GND

D +

D −

5 V

D +

D −

5 V

D +

D −

5 V

48-MHz

Crystal

Downstream

Ports

TUSB2040

Hub Controller

Tuning

Circuit

A

B

C

D

33

SN75240

A

B

C

D

GND

GND

GND

33

33

33

D +

D −

Upstream

Port

TPS2041B

SN75240

A

B

5 V

GND

C

D

1

µF

IN

GND

Ferrite Beads

Ferrite Beads

Ferrite Beads

Ferrite Beads

BUSPWR

GANGED

Tie to TPS2041 EN Input

OC

EN

OUT

5-V Power

Supply

IN

GND

3.3 V

4.7

µF

0.1

µF

4.7

µF

EN1

IN

OC1

OUT1

TPS2062

EN2

OC2

OUT2

0.1

µF

GND

µF per hub.

TPS76333

GENERIC HOT-PLUG APPLICATIONS

TPS2061, TPS2062, TPS2063

TPS2065, TPS2066, TPS2067

SLVS490B – DECEMBER 2003 – REVISED DECEMBER 2004

APPLICATION INFORMATION (continued)

Figure 29. Hybrid Self / Bus-Powered Hub Implementation

In many applications it may be necessary to remove modules or pc boards while the main unit is still operating.

These are considered hot-plug applications. Such implementations require the control of current surges seen by

the main power supply and the card being inserted. The most effective way to control these surges is to limit and

slowly ramp the current and voltage being applied to the card, similar to the way in which a power supply

normally turns on. Due to the controlled rise times and fall times of the TPS206x, these devices can be used to

provide a softer start-up to devices being hot-plugged into a powered system. The UVLO feature of the TPS206x

also ensures that the switch is off after the card has been removed, and that the switch is off during the next

insertion. The UVLO feature insures a soft start with a controlled rise time for every insertion of the card or

module.

21