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National Semiconductor Introduces 100V Half-Bridge PWM Controller with Industry’s Highest Level of Integration

LM5035 Integrates a 100V, 2A Primary-side Half-bridge Driver and Fully Featured PWM Controller to Maximize Conversion Efficiency and Power Density

Mar 20, 2006

March 20, 2006 -- National Semiconductor Corporation (NYSE: NSM), a worldwide leader in power management technology, today introduced a 100V half-bridge pulse-width modulation (PWM) controller that offers the industry’s highest level of integration to minimize the overall solution size of half-bridge DC-DC converters.  National is demonstrating the LM5035 in booth 8/9 at the Applied Power Electronics Conference (APEC) in Dallas today through Wednesday.

The LM5035, the newest member of National’s high-voltage LM5000 family, integrates a voltage-mode PWM controller with high-side and low-side 2A peak gate drivers plus two programmable, secondary-side synchronous rectifier FET drivers.  Programmable control of the rectifying switches allows designers to perfect their timing relationship to optimize overall power efficiency.  Applications for LM5035 half-bridge power supplies include telecommunications, data communications and industrial control systems where power density and efficiency are primary concerns.

“Most competitors’ half-bridge controllers require an external half-bridge FET driver, which increases the solution footprint and introduces timing errors due to propagation delays,” said Paul Greenland, director of strategic marketing for National Semiconductor’s Power Management Group. “With the LM5035, National has integrated core IP from our LM5100A gate driver and LM5025 PWM controller on a single chip. The result is a robust solution with industry-leading power density for highly compact power modules such as one-eighth and one-sixteenth bricks.”

About the LM5035
The LM5035 half-bridge controller and gate driver contains all of the features necessary to implement half-bridge-topology power converters using voltage-mode control with line feed-forward.  It also includes:

  • Synchronous rectifier controls with programmable delays that allow users to optimize power efficiency by tuning the secondary-side and primary-side FET switch timing    
  • Voltage-mode control for stable operation in half-bridge topology and better noise immunity than current mode control    
  • Line feed-forward compensation to improve regulation during input line voltage fluctuations    
  • Resistor-programmed oscillator capable of operating up to 2 MHz    
  • Synchronization capability to lock the PWM to an external oscillator for reduced electro-magnetic interference    
  • Programmable line under-voltage lockout to control power-on sequencing and minimize start-up current surges    
  • Remote thermal sensor interface that directly connects to an external thermister    
  • Adjustable soft-start for safe start-up in applications with large capacitive loads    
  • Versatile, dual-mode over-current protection with hiccup delay timer to reduce power dissipation during a continuous load fault    
  • Cycle-by-cycle over-current limiting to protect power supply components from instantaneous overload conditions    
  • Unique, current-mode opto-coupler interface that increases the bandwidth of conventional opto-couplers    
  • Precision 5V output that eliminates the need for an external reference or a bias supply for housekeeping circuits

About National’s Power Management Products 
National Semiconductor is the number one supplier of power management ICs with 14.1 percent market share, according to iSuppli’s 2005 voltage regulator/reference survey.  National’s power management revenue grew 37.3 percent in 2004 over the previous year, compared to 24 percent growth for the industry.  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 LM5035 is priced at $1.90 in 1,000-unit quantities.  For more information about the LM5035, including how to order samples and evaluation boards, please visit http://www.national.com/pf/LM/LM5035.html

Note to editors:  To view a high-resolution downloadable photo of this product, visit National's photo gallery.

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, communication 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, California, National reported sales of $1.91 billion for fiscal 2005, which ended May 29, 2005.  Additional company and product information is available at www.national.com