TPS2044, TPS2054

QUAD POWER-DISTRIBUTION SWITCHES

SLVS174B – JULY 1998 – REVISED FEBRUARY 1999

21

POST OFFICE BOX 655303

APPLICATION INFORMATION

USB power-distribution requirements

USB can be implemented in several ways, and, regardless of the type of USB device being developed, several

power-distribution features must be implemented.

–

Current-limit downstream ports

–

–

Enable/disable power to downstream ports

–

Power up at <100 mA

–

Limit inrush current (<44

Ω and 10 µF)

–

Limit inrush currents

–

Power up at <100 mA

The feature set of the TPS2044 and TPS2054 allows them to meet each of these requirements. The integrated

current-limiting and overcurrent reporting is required by hosts and self-powered hubs. The logic-level enable

and controlled rise times meet the need of both input and output ports on bus-power hubs, as well as the input

ports for bus-power functions (see Figure 33).