IN

OC1

EN1

OC2

EN2

GND

0.1

µF

2

8

3

5

4

7

33

µF

33

µF

GND

1

OUT1

TPS2062

Power Supply

D+

D−

GND

D+

D−

Downstream

USB Ports

USB

Controller

3.3 V

5 V

33

µF

GND

OUT2

D+

D−

33

µF

GND

D+

D−

6

0.1

µF

0.1

µF

0.1

µF

0.1

µF

TPS2061, TPS2062, TPS2063

TPS2065, TPS2066, TPS2067

www.ti.com

SLVS490I – DECEMBER 2003 – REVISED OCTOBER 2009

Figure 27. Typical Four-Port USB Host / Self-Powered Hub

BPHs obtain all power from upstream ports and often contain an embedded function. The hubs are required to

power up with less than one unit load. The BPH usually has one embedded function, and power is always

available to the controller of the hub. If the embedded function and hub require more than 100 mA on power up,

the power to the embedded function may need to be kept off until enumeration is completed. This can be

accomplished by removing power or by shutting off the clock to the embedded function. Power switching the

embedded function is not necessary if the aggregate power draw for the function and controller is less than one

unit load. The total current drawn by the bus-powered device is the sum of the current to the controller, the

embedded function, and the downstream ports, and it is limited to 500 mA from an upstream port.

LOW-POWER BUS-POWERED AND HIGH-POWER BUS-POWERED FUNCTIONS

Both low-power and high-power bus-powered functions obtain all power from upstream ports; low-power

functions always draw less than 100 mA; high-power functions must draw less than 100 mA at power up and can

draw up to 500 mA after enumeration. If the load of the function is more than the parallel combination of 44

Ω

and 10

μF at power up, the device must implement inrush current limiting (see Figure 28). With TPS206x, the

internal functions could draw more than 500 mA, which fits the needs of some applications such as motor driving

circuits.

Copyright © 2003–2009, Texas Instruments Incorporated

Submit Documentation Feedback

19

Product Folder Link(s): TPS2061 TPS2062 TPS2063 TPS2065 TPS2066 TPS2067