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National Semiconductor Launches Highly-Integrated –48 V Hot Swap Controller for Communications System Power Distribution

Nov 24, 2003

November 24, 2003 - Extending its leadership in providing complete high-voltage power conversion solutions, National Semiconductor Corporation (NYSE: NSM) today unveiled a  -48 V hot swap controller that delivers board area savings and long-term system reliability for communication systems.  Sampling now, this device integrates a 100 V bias regulator with an active current control loop, start and fault timers and under-voltage/over-voltage (UV/OV) protection to provide a system solution for board insertion into live –48 V backplanes.  Integrating both hot swap in-rush, fault protection and voltage supervision features in a small MSOP-8 package reduces the board area, component count and complexity in a variety of power systems.  

“As National Semiconductor’s first entry into the hot swap controller market, the LM5068 is the best in its class in terms of functionality and footprint,” said Paul Greenland, marketing director of National Semiconductor’s power management group.  “National’s LM5068 offers unique advantages to the customer that none of the existing products on the marketplace can match.  The LM5068 is a highly integrated hot-swap controller with an internal high-voltage bias regulator and multiple user-programmable features designed to power and protect National’s new family of high-voltage DC-DC regulators and controllers including the LM5000, LM5030 and LM5041.”

National Semiconductor’s LM5068 provides intelligent control of power supply during insertion and removal of modules into a live –48 V backplane.  It can also be attached directly to a –48 V bus.  The programmable UV and OV comparators set the operating input voltage range with input transient capability to 100 V.  The robust operating range provides reliable power distribution and hot swap control in communications and networking equipment, high availability servers, -48 V distributed power systems and central office switches.

Key Features and Benefits
National’s LM5068 provides trimmed and guaranteed 2 percent UV and OV thresholds plus a unique programmable UV/OV threshold hysteresis.  The threshold voltages are programmed by the ratio of an external resistor divider connected between the 48 V supply rails and the LM5068 comparator inputs.  UV/OV hysteresis is generated by trimmed 20 ?A current sources that are switched into the external UV/OV resistor divider when a start/stop threshold is achieved.  Thus, the impedance of the external resistors determines the magnitude of UV and OV hysteresis.  The accurate and programmable UV/OV thresholds allow the designer to activate downstream DC-DC converters within a narrow voltage window while preventing oscillations during on/off transitions. 

National Semiconductor’s LM5068 hot swap controller differentiates itself in that it integrates:

  • Wide-range, 15 V-to-100 V bias regulator
  • Programmable UV/OV protection with plus or minus 2 percent threshold tolerance
  • Programmable UV/OV hysteresis feature
  • Programmable de-bounce delay and fault timers
  • Accurate and programmable active-current control loop for in-rush and short-circuit currents
  • Available with latched off fault mode and continuous re-try versions

Sampling today, the LM5068 housed in a MSOP-8 package is priced at $1.35 each in 1,000 piece quantities.  Volume production is expected in late January 2004.

About National Semiconductor
National Semiconductor is the premier analog company. Combining real-world analog and state-of-the-art digital technology, the company is focused on analog-based semiconductor products, which include stand-alone devices and subsystems in the areas of power management, display drivers, audio, amplifiers, imaging and data conversion. The company targets key markets such as wireless, displays, PCs, networks and a broad range of portable applications. With headquarters in Santa Clara, California, National reported sales of $1.67 billion for the 2003 fiscal year, which ended May 25, 2003.  Additional company and product information is available on the World Wide Web at www.national.com