National Semi launches power module family

Santa Clara, Calif. — Claiming accelerated time-to-market and superior thermal and electromagnetic interference (EMI) performance, National Semiconductor Corp. has introduced the first three products in its SIMPLE SWITCHER power module family. Designed to take ease-of-use to the next level, National also launched its WEBENCH Power Architect that allows engineers to quickly design multiple-output, high-performance dc/dc power supplies for an entire system.

The LMZ-series of power modules is designed as an integrated solution that will help system designers get their products to market faster. “We’ve taken the external components around the switching regulator and put them into semiconductor-like package technology, taking into consideration the design challenges with other solutions including open-frame and IC-like modules,” says Michael White, vice president of National’s Performance Power Product Line.

White says this has resulted in a solution with superior thermal performance and outstanding EMI. “We also designed it with ease-of-use in mind. We put together a family of devices with pin-to-pin compatibility so it’s very easy for a designer late in the design stage to prototype with different types of solutions without changing their board.”

The size and lead pitch of these modules enable the use of the same pick-and-place manufacturing used with standard TO-263 packages. Each module is pin-to-pin compatible with other family members, allowing designers to create one layout to facilitate last-minute drop-in replacements if load current requirements change.

The package looks like a traditional TO-220 or TO-263 type package that power-supply designers are used to working with, White says. It’s also a small form factor with industry-standard leads, which makes it easy to prototype with in a lab and it also has a unified heat slug on the bottom that manufacturers prefer for a heat sinking design, he says.

The modules’ efficient heat dissipation and large exposed-bottom pad allows for operation in high-ambient temperatures and eliminates the need for airflow. They typically operate as much as 10 degrees cooler than comparable modules, according to National. The power modules’ single exposed-bottom pad also allows for easy and quick prototyping on lab benches, eliminating the possibility of non-visual solder bridging.

The LMZ-series power modules provide the efficiency of a synchronous switching regulator with the simplicity of a linear regulator, eliminating the external inductor and complex layout placement challenges typical of switching regulator designs, says National.

National says its power modules simplify power-supply design for field-programmable gate arrays (FPGAs), microprocessors, digital signal processors (DSPs) and other point of load (POL) conversions for medical, broadcast video, communications, industrial and military applications.

EMI and noise are critical in these types of applications. As a result, National used some package technology to shield the inductor to make it suitable for some of these noise-sensitive applications. The modules also meet the requirements of the EN55022 (CISPR22) Class B radiated emission standard.

Power supply designers can design with SIMPLE SWITCHER power modules using National’s WEBENCH Power Designer and the newly introduced WEBENCH Power Architect design tool.


Here’s a quick rundown of the three products.

The SIMPLE SWITCHER power modules offer a low output voltage ripple and a wide voltage and current range. The first release of the LMZ power modules supports 3.3-V, 5-V, 12-V and 24-V input voltage rails and offers load currents up to 4 A. The operating temperature range is -40 degrees C to 125 degrees C operation. Available in 7-lead, 10.16 x 13.77 x 4.57-mm packages, the LMZ-series features best-in-class thermal resistance (theta-JA) temperature of 20 degrees C per watt.

The LMZ10504 supports maximum load currents of 4 A with an input voltage range of 2.95 V to 5.5 V. The LMZ12003 supports maximum load currents of 3 A with an input voltage range of 4.5 V to 20 V. The LMZ14203 supports maximum load currents of 3 A with an input voltage range of 6 V to 42 V.

Availability: The LMZ10504, LMZ12003 and LMZ14203 are available now. National plans on introducing SIMPLE SWITCHER power modules throughout 2010.

Pricing: The LMZ10504 is priced at $7.10 each, the LMZ12003 is $7.25 each, and the LMZ14203 is $9.50 each in quantities of 500.

WEBENCH Power Architect

National also unveiled its latest addition to its WEBENCH Designer tools — WEBENCH Power Architect — touted as the industry’s first design tool that speeds up the design of a multi-output, high-performance dc/dc power supplies for an entire system. With the new tool, system designers can instantly optimize multiple power supplies across several performance parameters including topology, intermediate voltage rails, footprint, efficiency, component count and bill-of-materials (BOM) cost.

“WEBENCH Power Architect is the first tool to make it easy to quickly design power supplies for all of the loads in a system,” said Phil Gibson, vice president of Technical Sales Tools at National Semiconductor.

“The new tool has added the ability to look at multiple, different power architectures and intermediate buses across all of those tradeoffs — price, footprint, efficiency, and BOM count — and do your own filtering on those tradeoffs,” Gibson adds. “All of that is pulled from a library of roughly 25 different topologies and configurations of power-supply alternatives. The tool makes those choices for you and selects components from 110 manufacturers and a 21,000 component library to pick the best possible component depending on where you have the optimizer dial set for,” he adds.


“Depending on the tool’s optimizer dial setting, a typical system with eight power loads will have a BOM count ranging from 50 to 150 components. This is the only tool that lets you instantly compare performance and cost for many alternative system combinations, and quickly implement them,” Gibson says.

The library of 21,000 components means designers have a wide range of system alternatives for creating large scale complex systems:

  • System input sources (VIN) from 1V — 100V
  • Up-to-20 system loads (VOUT) from 0.6V — 300V
  • Power per load up to 300 W
  • System efficiency greater than 90 percent
  • Per-supply footprints from 14 x 14 mm

When engineers finish “dialing-in” their preference for footprint, system BOM cost and power efficiency, the tool’s graphical analysis capability instantly identifies major sources of power dissipation, cost and footprint area. It allows the user to edit individual power supplies and loads to further model and optimize the overall system for thermal and electrical performance design goals, says National.

When the design is complete, the tool generates a system summary report including schematics, BOMs and electrical operating values. Several international distributors provide pricing and the WEBENCH “Build It!” feature offers complete BOM prototype kits with overnight shipping.