Features Compatible with USB1.1 and USB 2.0 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 5µA Maximum Standby Supply Current 16-Pin SOIC Package Ambient Temperature Range: -40°C to 85°C Description The 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. 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 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. 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 high-current overheating, and undervoltage lockout to keep switches from operating if the input voltage is below acceptable levels. Applications USB Root, Self-Powered, and Bus-Powered Hubs USB Devices such as Monitors and Printers General Purpose High Side Switch Applications

Also Recommended LM3525▲ Single Port USB Power Switch LM3526▲ Dual Port USB Power Switch LM3543▲ Triple USB Power Switch

Datasheets

Title		Size	Date	Other Language
	LM3544 Quad Port USB Power Distribution Switch and Over-Current Protection	785 Kbytes	7-Apr-05

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM3544M-L/NOPB LM3544M-L RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 1979 AVNET-EM Worldwide 277 DIGI-KEY Worldwide 0 MOUSER Worldwide 230 TAYLOR Americas 1979	$1.80 each at 1K+ pcs	rail of 48
LM3544MX-L/NOPB LM3544MX-L RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty AITG Asia Pacific 1001 ARROW Worldwide 2500 DIGI-KEY Worldwide 0 TAYLOR Americas 2500	$1.80 each at 1K+ pcs	reel of 2500

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM3544M-H	LM3544M-L	National Semiconductor	30 Nov 2009
LM3544MX-H	LM3544MX-L	National Semiconductor	30 Nov 2009

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM3544.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM3544 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM3544M-L/NOPB LM3544M-L	139.49 140	SOIC NARROW	16	1 1	260 235	Detail	Download	N/A	NSUZXYTTE# LM3544M-L
LM3544MX-L/NOPB LM3544MX-L	139.49 140	SOIC NARROW	16	1 1	260 235	Detail	Download	N/A	NSUZXYTTE# LM3544M-L

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM3544.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM3544 is located at RoHS Status.

CAD Symbols and Models Download LM3544 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3544M-L	CS065	2	47473	43	0	5527000	1	1568301341
LM3544MX-L	CS065	2	47473	43	0	5527000	1	1568301341

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM3544.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM3544 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM3544M-H	LM3544M-L	National Semiconductor	30 Nov 2009
LM3544MX-H	LM3544MX-L	National Semiconductor	30 Nov 2009