Features Inverts or doubles input supply voltage Narrow SO-8 and Mini SO-8 Package 6.5 typical output resistance 88% typical conversion efficiency at 100 mA (LM2660) selectable oscillator frequency: 10 kHz/80 kHz (LM2661) low current shutdown mode Description The LM2660/LM2661 CMOS charge-pump voltage converter inverts a positive voltage in the range of 1.5V to 5.5V to the corresponding negative voltage. The LM2660/LM2661 uses two low cost capacitors to provide 100 mA of output current without the cost, size, and EMI related to inductor based converters. With an operating current of only 120 µA and operating efficiency greater than 90% at most loads, the LM2660/LM2661 provides ideal performance for battery powered systems. The LM2660/LM2661 may also be used as a positive voltage doubler. The oscillator frequency can be lowered by adding an external capacitor to the OSC pin. Also, the OSC pin may be used to drive the LM2660/LM2661 with an external clock. For LM2660, a frequency control (FC) pin selects the oscillator frequency of 10 kHz or 80 kHz. For LM2661, an external shutdown (SD) pin replaces the FC pin. The SD pin can be used to disable the device and reduce the quiescent current to 0.5 µA. The oscillator frequency for the LM2661 is 80 kHz. Applications Laptop computers Cellular phones Medical instruments Operational amplifier power supplies Interface power supplies Handheld instruments

Typical Application *click for larger image	Connection Diagram *click for larger image
Typical Performance *click for larger image

Datasheets

Title		Size	Date	Other Language
	LM2661 Switched Capacitor Voltage Converter	358 Kbytes	15-Oct-04	日本語

Application Notes

Title		Size	Date	Other Language
	AN-1142: Application Note 1142 LM2661/3/4 Evaluation Board	186 Kbytes	4-Oct-04

Other Technical Documents

Title		Type	Date
	Provide a Negative Bias Voltage to Low-voltage Amplifiers to Improve their Near-zero-volt Performance	External Article	2008-11-25

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2661M	LM2772	National Semiconductor	30 Nov 2009
LM2661MM	LM2772	National Semiconductor	30 Nov 2009
LM2661MMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2661MX	LM2772	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 LM2661.

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 LM2661 is located at RoHS Status.

Part Number(s) (NSID)	Description	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM2661/3/4EVAL	Switched Capacitor Voltage Converter	Full production	Contact your distributor	$40.00 each	1
Description: LM266X Evaluation Board - Switched Capacitor Power Converter Features: Double, Invert Fractional Conversion Output: 40mA, 100mA, 200mA Package Options: SOT23-6, MSOP-8, SO-8 Contents: LM2661/3/4 Evaluation Board Switch to National the Future of Power Management CD ROM First page of LM2660/61, LM2662/3, LM2664, LM2665, LM3350, LM3351 Datasheet LM2661/3/4 App Note LM2661/3/4 Schematic and Layout Table of LM2661/3/4 Switched Capacitor Family Switched Capacitor Selection Guide LM2661/3/4 BOM

National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

Lead Free product status is available through the search tool located here

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format

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 LM2661.

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 LM2661 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2661M	LM2772	National Semiconductor	30 Nov 2009
LM2661MM	LM2772	National Semiconductor	30 Nov 2009
LM2661MMX	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2661MX	LM2772	National Semiconductor	30 Nov 2009