National Semiconductor announced its latest innovation in switching regulators for boost applications that combine the best of boost switching technology and world-class design tools. This new solution is designed to enable a high performance step-up regulator in minimum time and PCB area.

The LM2698 is the first in the fourth generation of National's Simple Switcherý regulators. It uses current-mode control (without the need for a sense resistor) and pulse-width modulation (PWM) to deliver superior transient response, line and load regulation and simplicity of design. The 0.2-ohm 1.3A (guaranteed) internal switch and 1.3MHz clock combine for unparalleled power density.

Optimized features --- such as 2.2V to 12V input voltage range, user selectable 0.6 or 1.3MHz clock and low-noise, easily filtered output --- make the LM2698 an ideal solution for DSL and cable modems, battery-powered systems or applications requiring 2.5V to 3.3V, 5V to 12V or other boost conversion.

"Eighty percent of the demand for switching regulators comes from non-power supply designers," said John Perzow, strategic marketing manager in National's power management group. "Designers with little or no power supply experience can easily combine National's high-performance switching regulators with Simple Switcher design tools to create elegant power supply solutions. The LM2698 represents a new level of boost regulator performance and improves engineering productivity."

Fundamental to the advantage of National's Simple Switcher line is the Microsoft Windows compatibility of the Switchers Made Simpleý design software. The software provides customers with a complete solution including schematics, component lists, guaranteed circuit performance and more. National's design software and licensed software (Simple Switchers Made Simple, WebSIMTM and WebTHERMý) plus National's demo boards provide a total solution that has made the Simple Switcher family the most widely accepted DC/DC converter. Since system power supply needs are often not defined until late in a project, the Simple Switcher solution can be the key to getting products to market quickly and reliably.

National Semiconductor, 2900 Semiconductor Dr., Santa Clara, California 95052-8090. Tel: 408-721-5000

The LM2698 is a general-purpose pulse-width modulator boost converter that uses current-mode control and notably, doesn't need a sense resistor. The 1.9A, 18V, 0.2ohm internal switch enables the LM2698 to provide efficient power conversion to outputs ranging from 2.2V to 17V. It can operate with input voltages as low as 2.2V and as high as 12V.

The modulator uses current-mode architecture, which provides superior line and load regulation and simple frequency compensation over the device's 2.2V to 12V input voltage range. The LM2698 also offers the high power density needed for today's designs and is capable of supplying 12V at 400mA from a 5V input. The chip can be used in flyback or single-ended primary inductance converter (SEPIC) topologies. The company designed a very nice innovation, the Simple Switcherý feature that offers a pin selectable switching frequency of either 600kHz or 1.25MHz. This provides flexibility in component selection and filtering techniques. A shutdown pin is also available to suspend the device and decrease the quiescent current to 5micro-amp.

An external compensation pin gives the user flexibility in setting frequency compensation, which makes possible the use of small, low equivalent series resistance (ESR) ceramic capacitors at the output. The company also offers a software design package that shouldn't be overlooked. Switchers Made Simple ý software is available to aid a quick, easy and guaranteed design.

The device can be used for 3.3V to 5V and 5V to 12V conversion. It also can be used in set-top boxes, DSL modems, diagnostic medical instrumentation, and boost converters.

The LM2698 is available now in the tiny MSOP-8 package with a smaller footprint than previous designs, and is priced at $1.83 each in 1000-lot units.

Data sheet, package types, pricing, and evaluation board availability can be found at: (http://www.national.com/pf/LM/LM2698.html )