National Semiconductor Introduces Synchronous Switching Controller with Precision Enable Pin for Sequencing Output Supplies

Media Contact
Gayle Bullock
National Semiconductor
(408) 721-2033
gayle.bullock@nsc.com

National Semiconductor Introduces Synchronous Switching Controller with Precision Enable Pin for Sequencing Output Supplies

LM1771, in MSOP and LLP Packages, Utilizes Constant On-Time Topology to Eliminate Need for Compensation Components, Ease Design In

September 20, 2006 -- National Semiconductor Corporation (NYSE: NSM) today introduced the LM1771, a synchronous buck switching controller with a precision enable pin for easier sequencing of output power supplies.  In addition, the LM1771 utilizes constant on-time control, making it easy to employ because it does not require external compensation. 

The LM1771, packaged in tiny MSOP-8 and 6-pin LLP® packages, provides low-voltage point-of-load regulation from standard 5V and 3.3V rails in space-constrained applications such as set-top boxes, cable modems, handheld scanners and printers.  It also replaces switching regulators and LDOs in enterprise server and point-of-sale applications where efficiency is crucial.  The precision enable pin allows for sequencing of power-up and power-down of core and input/output supplies to digital logic devices such as ASICs, FPGAs and microprocessors.

Key Features of the LM1771:

• Synchronous operation: High-side PFET and low-side NFET enable higher efficiency for reduced power dissipation   
• Fast transient response: Allows for fewer, smaller filter capacitors   
• Input voltage range of 2.8V to 5.5V: Ideal for point-of-load regulation from a 3.3V or 5V rail   
• Output voltage as low as 0.8V: Supports applications requiring power rails of less than 1V   
• Internal soft-start: Limits in-rush current and allows for a controlled start-up   
• Short circuit protection: Prevents damage to the application   
• Three on-time options: Allow for selection of operating frequency range   
• Small MSOP-8 and 6-pin LLP packages:  Ideal for space-constrained applications

About National’s Power Management Products
National Semiconductor is the number one supplier of voltage regulator ICs with 14 percent market share, according to iSuppli’s 2005 Semiconductor Market Share survey.  National's innovative power management products include best-in-class linear regulators; power monitoring, control and reference ICs; and switching converters, such as high-voltage ICs for DC-DC conversion, switched capacitor converters, lighting management ICs and inductive switching converters.  National also offers online tools that enable power designers to select the best power management chips for their applications.  National's Webench® design tool allows designers to choose a product, create and analyze a design, and then build custom prototypes that can be delivered within 24 hours. More information about National’s power management products is available at http://power.national.com.

Pricing and Availability
Available now, the LM1771 is priced at 98 cents in 1,000-unit quantities.  For more information about the LM1771, including how to order evaluation boards and samples, please visit http://www.national.com/pf/LM/LM1771.html. 

About National Semiconductor
National Semiconductor, the industry's premier analog company, creates high-value analog devices and subsystems.  National's leading-edge products include power management circuits, display drivers, audio and operational amplifiers, interface products and data conversion solutions. National's key analog markets include wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial, and test and measurement applications. Headquartered in Santa Clara, Calif., National reported sales of $2.16 billion for fiscal 2006, which ended May 28, 2006.  Additional company and product information is available at www.national.com.

# # #

Original text is here