Datasheet Texas Instruments LM3544M-L — Datenblatt

LM3544 LM3544 Quad Port USB Power Distribution Switch and Over-Current Protection Literature Number: SNVS062B LM3544
Quad Port USB Power Distribution Switch and
Over-Current Protection
General Description Features The LM3544 is a quad high-side power switch that is an
excellent choice for use in Root, Self-Powered and BusPowered USB (Universal Serial Bus) Hubs. Independent
port enables, flag signals to alert USB controllers of error
conditions, controlled start-up in hot-plug events, and short
circuit protection all satisfy USB requirements. The LM3544 accepts input voltages between 2.7V and 5.5V.
The Enable logic inputs, available in active-high and activelow versions, can be powered off any voltage in the 2.7V to
5.5V range. The LM3544 limits the continuous current
through a single port to 1.25A (max.) when it is shorted to
ground.
The low on-state resistance of the LM3544 switches ensures
the LM3544 will satisfy USB voltage drop requirements,
even when current through a switch reaches 500 mA. Thus,
High-Powered USB Functions, Low-Powered USB functions, and Bus-Powered USB Hubs can all be powered off a
Root or Self-Powered USB Hub containing the LM3544.
Added features of the LM3544 include current foldback to
reduce power consumption in current overload conditions,
thermal shutdown to prevent device failure caused by highcurrent overheating, and undervoltage lockout to keep
switches from operating if the input voltage is below acceptable levels. n Compatible with USB1.1 and USB 2.0
90mΩ (typ.) High-Side MOSFET Switch
500mA Continuous Current per Port …