National Debuts SIMPLE SWITCHER Regulators, Enhanced WEBENCH Design Tool

National Semiconductor Corp. (NYSE:NSM) announced the addition of a sophisticated but easy-to-use graphical tool to its WEBENCH® online design environment as well as 11 new SIMPLE SWITCHER® step-down voltage regulators. The voltage regulators are well-suited for a wide variety of applications including automotive, industrial and communication. National’s WEBENCH design environment helps make design easy. It has been expanded to include enhanced optimization tools including bill-of-material components charts, efficiency and footprint graphs and the ability to output a fully formatted report summarizing the design.

National’s new family of SIMPLE SWITCHER step-down voltage regulators offers a wide input voltage range from 4.5V to 42V, which allows for wide-voltage transients from 12V and 24V input rails. Internal compensation and small, low pin-count packages simplify the design process and reduce overall system size.

Enhanced Power WEBENCH Design Environment
National’s WEBENCH design environment enables novice as well as experienced power supply designers to easily “dial-in” their size and efficiency requirements while also realizing fast time to market. Real-time electrical simulations feature enhanced waveform processing that enables designers to see the electrical behavior of the circuit under dynamic conditions such as load transient, line transient or start up. Bode plots are also provided to evaluate and optimize loop stability. Thermal simulation enables engineers to track and solve thermal challenges in a design through the use of copper heat sinking, air flow and copper thickness.

National has added optimization graphs and charts to the WEBENCH design environment, which allow designers to view the impact of optimizing the design for efficiency or footprint. The tool graphically shows the efficiency, footprint, component power dissipation and frequency for different design scenarios.

These charts offer views of the electrical properties such as efficiency, output voltage ripple, duty cycle and power dissipation over a range of output currents and input voltages. This feature lets designers quickly view design tradeoffs and select the best design optimized for their needs.

When the design is complete, a report summary is created and a custom prototype power supply kit can be ordered.

Technical Features of National’s New SIMPLE SWITCHER Step-down Voltage Regulators
The 11 new SIMPLE SWITCHER step-down voltage regulators support a variety of load currents from 0.5A to 5A. Designed with voltage mode control, the family includes the LM22670, LM22671, LM22672, LM22673, LM22674, LM22675, LM22676, LM22677, LM22678, LM22679 and the LM22680. Each provides a fixed switching frequency at 500 kHz and adjustable switching frequency or frequency synchronization up to 1 MHz which allows for electromagnetic interference (EMI) reduction in noise-sensitive automotive, industrial and communication applications. Available in an industry-standard 8-pin PSOP package and new 7-pin TO-263 thin package, the step-down voltage regulators also feature adjustable frequency, precision enable, external soft-start and adjustable current limits.

The LM22671 and LM22674 support load currents at 0.5A. The LM22672 and LM22675 support load currents at 1A. The LM22680 supports load currents at 2A. The LM22670, LM22673 and LM22676 support load currents at 3A. The LM22677, LM22678 and LM22679 support load currents at 5A.

National’s 11 new SIMPLE SWITCHER step-down voltage regulators are pin-to-pin compatible with National’s LM267X series of regulators, which include the LM2670, LM2671, LM2672, LM2673, LM2674, LM2675, LM2676, LM2677, LM2678 and LM2679.

New TO-263 Thin Packaging
National’s new TO-263 thin package is manufactured from lead-free solder and halogen-free mold compounds. The TO-263 thin package is footprint and PCB drop-in compatible with that of the standard T0-263 package. Overall package thickness is 50 percent thinner than standard TO-263 packaging (2.00 mm vs. 4.57 mm). It features improved moisture sensitivity levels and comparable thermal performance to the standard TO-263 packaging. Available in standard tape-and-reel, the package received industry approval from the JEDEC JC-11 committee in May 2008 under registration number 10-447.

About National’s Power Management Products
National solves power management design problems in space- and energy-constrained applications from feature-rich handheld devices through large line-powered systems. From the novice power designer to the power expert, National’s products, people and design tools enable customers to design green-powered systems with complex power supplies in the shortest amount of time. High-performance products include switching regulators such as National’s flagship SIMPLE SWITCHER® family and application-specific products including white-LED drivers and Power-over-Ethernet controllers.

Availability and Pricing
Available now, the 11 new SIMPLE SWITCHER step-down voltage regulators range in price from $1.30 to $3.25 in 1,000-unit quantities.

About National Semiconductor
National Semiconductor creates energy-efficient analog and mixed-signal semiconductors. Its PowerWise® products enable systems that consume less power, extend battery life and generate less heat. Headquartered in Santa Clara, Calif., National reported sales of $1.89 billion for fiscal 2008 which ended May 25, 2008.

National Semiconductor is a registered trademark of National Semiconductor Corporation.