Features • Fully specified for operation over -40°C to +125°C • Output current in excess of 500 mA (400mA for SOT-223 package) • Output trimmed for 5% tolerance under all operating conditions • Wide output capacitor ESR range, 0.01 up to 5 • Internal short circuit and thermal overload protection • Reverse battery protection • 60V input transient protection • Mirror image insertion protection Description The LM2937-2.5 and LM2937-3.3 are positive voltage regulators capable of supplying up to 500 mA of load current. Both regulators are ideal for converting a common 5V logic supply, or higher input supply voltage, to the lower 2.5V and 3.3V supplies to power VLSI ASIC's and microcontrollers. Special circuitry has been incorporated to minimize the quiescent current to typically only 10 mA with a full 500 mA load current when the input to output voltage differential is greater than 5V. The LM2937 requires an output bypass capacitor for stability. As with most regulators utilizing a PNP pass transistor, the ESR of this capacitor remains a critical design parameter, but the LM2937-2.5 and LM2937-3.3 include special compensation circuitry that relaxes ESR requirements. The LM2937 is stable for all ESR ratings less than 5. This allows the use of low ESR chip capacitors. The regulators are also suited for automotive applications, with built in protection from reverse battery connections, two-battery jumps and up to +60V/-50V load dump transients. Familiar regulator features such as short circuit and thermal shutdown protection are also built in.

Also Recommended LM2937▲ Different Output Voltages LP2989▲ Better Performance, Lower Voltage LM2937-2.5▲ 2.5V Output Voltage MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Connection Diagram click for larger image
Typical Performance *click for larger image Output Voltage vs Temperature, LM2937-3.3

Datasheets

Title		Size	Date	Other Language
	LM2937-2.5, LM2937-3.3 400mA and 500mA Voltage Regulators	735 Kbytes	29-Aug-05

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM2937ES-3.3/NOPB LM2937ES-3.3 RoHS Status	TO-263	Full production Lead Time: 16 weeks	Distributor Region Qty ARROW Worldwide 1530 AVNET-EM Worldwide 1062 DIGIKEY Worldwide 1137 FUTURE Worldwide 1100 NEWARK Americas 1434 RS COMPONENTS Worldwide 360 TAYLOR Americas 405	$0.88 each at 1K+ pcs	rail of 45
LM2937ESX-3.3/NOPB LM2937ESX-3.3 RoHS Status	TO-263	Full production Lead Time: 16 weeks	Distributor Region Qty AITG Asia Pacific 1000 DIGIKEY Worldwide 0 FUTURE Worldwide 1100	$0.88 each at 1K+ pcs	reel of 500
LM2937ET-3.3/NOPB LM2937ET-3.3 RoHS Status	TO-220	Full production Lead Time: 16 weeks	Distributor Region Qty ARROW Worldwide 592 AVNET-EM Worldwide 460 DIGIKEY Worldwide 1301 FARNELL Europe and Asia 231 FUTURE Worldwide 1100 NEWARK Americas 561 RS COMPONENTS Worldwide 430	$0.74 each at 1K+ pcs	rail of 45
LM2937IMP-3.3/NOPB LM2937IMP-3.3 RoHS Status	SOT-223	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 5052 DIGIKEY Worldwide 6576 FARNELL Europe and Asia 2976 FUTURE Worldwide 1100 KEIKONG Asia Pacific 3000	$0.69 each at 1K+ pcs	reel of 1000
LM2937IMPX-3.3/NOPB LM2937IMPX-3.3 RoHS Status	SOT-223	Full production Lead Time: 12 weeks	Distributor Region Qty ARROW Worldwide 3110 DIGIKEY Worldwide 0	$0.69 each at 1K+ pcs	reel of 2000

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

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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

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

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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

CAD Symbols and Models N/A

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2937ES-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2937ESX-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2937ET-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2937IMP-3.3	SLM	0	44046	0	0	3532500	1	1002356520
LM2937IMPX-3.3	SLM	0	44046	0	0	3532500	1	1002356520

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/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

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