TUSB2036

2/3-PORT HUB FOR THE UNIVERSAL SERIAL BUS

WITH OPTIONAL SERIAL EEPROM INTERFACE

SLLS372 – MARCH 2000

16

POST OFFICE BOX 655303

APPLICATION INFORMATION

self-powered hub, ganged port-power management

The TUSB2036 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.

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

OVRCUR1

OVRCUR2

OVRCUR3

GND

XTAL1/CLK48

XTAL2

EXTMEM

RESET

TPS2044†

IN1

EN1

OUT1

D +

D –

5 V

GND

D +

D –

5 V

Downstream

Ports

OC1

TUSB2036

DP3

DM3

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

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

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

NP3

NPINT1

NPINT0

MODE

DP0PUR

OCPROT/PWRSW

Figure 11. TUSB2036 Self-Powered Hub, Ganged Port-Power Management Application