Features High Efficiency Multi-Gain Architecture: Peak Power Efficiency >85% Output Voltage Pairs: 1.2V/1.5V and 1.2V/1.575V Dynamic Output Voltage Selection ±3% Output Voltage Accuracy Output Currents up to 250mA 2.7V to 5.5V Input Range Low-Supply-Current Sleep Mode 55µA Quiescent Supply Current in Full-Power Mode Soft-Start Short-Circuit Protection in Full-Power Mode Current-Limit Protection in Sleep Mode LLP-10 Package (3mm × 3mm × 0.8mm) Description The LM2770 is a switched capacitor step-down regulator that is ideal for powering low-voltage applications in portable systems. The LM2770 can supply load currents up to 250mA and operates over an input voltage range of 2.7V to 5.5V. This makes the LM2770 a great choice for systems powered by 1-cell Li-Ion batteries and chargers. The output voltage of the LM2770 can be dynamically switched between two output levels with a logic input pin. Output voltage pairs currently available include 1.2V/1.5V and 1.2V/1.575V. Other pairs of voltage options can be developed upon request. LM2770 efficiency is superior to both fixed-gain switched capacitor buck regulators and low-dropout linear regulators (LDO's). Multiple fractional gains maximize power efficiency over the entire input voltage and output current ranges. The LM2770 can also be switched into a low-power sleep mode when load currents are light (<= 20mA). In sleep mode, the charge pump is off, and the output is driven with a low-noise, low-power linear regulator. Soft-start, short-circuit protection, current-limit protection, and thermal-shutdown protection are also included. The LM2770 is available in National's small 10-pin Leadless Leadframe Package (LLP-10). Applications DSP Power Supplies Baseband Power Supplies Mobile Phones and Pagers Portable Electronic Equipment

Also Recommended LM2788▲ Better Efficiency 120mA, Smaller Package Mini SOIC LM2797▲ Better Efficiency 120mA, With Voltage Monitoring And 100us Turn-On Time LM2798▲ Better Efficiency 120mA, With Voltage Monitoring And 400us Turn-On Time

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance click for larger image

Datasheets

Title		Size	Date	Other Language
	LM2770 High Efficiency Switched Capacitor Step-Down DC/DC Regulator with Sleep Mode	796 Kbytes	17-Dec-04

Other Technical Documents

Title		Type	Date
	Understanding Portable Applications Requirements to Improve System Performance	Power Designer	2007-03-22
	Power Management Design for Applications Processors	Power Designer	2007-03-22

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM2770SD-1215/NOPB LM2770SD-1215 RoHS Status	LLP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0 RS COMPONENTS Worldwide 5	$0.71 each at 1K+ pcs	reel of 1000

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2770SD-12157	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2770SDX-1215	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2770SDX-12157	NONE	NATIONAL SEMICONDUCTOR	01 Dec 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 LM2770.

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 LM2770 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
LM2770SD-1215/NOPB LM2770SD-1215	21.112 21.182	LLP	10	1 1	260 260	Detail	Download	N/A	ZXYTT L162B

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 LM2770.

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 LM2770 is located at RoHS Status.

CAD Symbols and Models Download LM2770 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2770SD-1215	CMOS7	0	21301	0	0	1584000	3	449464325

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 LM2770.

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 LM2770 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2770SD-12157	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2770SDX-1215	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2770SDX-12157	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009