Features: *90m (typ.) High-Side MOSFET Switch
* 500mA Continuous Current per Port
* 7 ms Fault Flag Delay Filters Hot-Plug Events
* Industry Standard Pin Order
* Short Circuit Protection with Power-Saving Current Foldback
* Thermal Shutdown Protection
* Undervoltage Lockout
* Recognized by UL and Nemko CB
* Input Voltage Range: 2.7V to 5.5V
* 5A Maximum Standby Supply Current
* 16-Pin SOIC Package
* Ambient Temperature Range: -40 to 85ApplicationUSB Root, Self-Powered, and Bus-Powered Hubs
USB Devices such as Monitors and Printers
General Purpose High Side Switch ApplicationsPinout
SpecificationsIf Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.
Voltage at INX and OUTX pins -0.3V to 6V
Voltage at ENX (ENX) and FLAGX -0.3V to 5.5V
pins
Power Dissipation (Note 2) Internally Limited
Maximum Junction Temperature 150
Storage Temperature Range-65 to 150
Lead Temperature Range
(Soldering, 5 sec.)260
ESD Rating (Note 3) 2 kV
| Channels |
4 Channels |
| Switch On Resistance |
0.09 Ohm |
| Output Current |
500 mA |
| Input Min Voltage |
2.7 Volt |
| Input Max Voltage |
5.5 Volt |
| Quiescent Current |
0.001 mA |
| Enable Control |
Active Low |
| Temperature Min |
-40 deg C |
| Temperature Max |
125 deg C |
| RegType |
Switch |
| View Using Catalog |
DescriptionThe LM3544 is a quad high-side power switch that is an excellent choice for use in Root, Self-Powered and Bus-Powered USB (Universal Serial Bus) Hubs. Indepen-dent 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 active-low 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.
Thelowon-stateresistanceoftheLM3544switchesensures 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 func-tions, 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 high-current overheating, and undervoltage lockout to keep switches from operating if the input voltage is below acceptable levels.
LM3544 Data Sheet
