National Semiconductor Introduces Synchronous, Monolithic, 1.5A Buck Regulator
National Semiconductor Corporation has introduced the LM3100, the first member of a new synchronous Simple Switcher® family and the industry's first synchronous, monolithic, 1.5A buck regulator with an input voltage range of 4.5V to 36V.
Designed to simplify circuit designs, this new buck regulator will be complemented in 2006 by additional family members.
"The LM3100 builds on the success of National's comprehensive Simple Switcher product offerings," said Paul Greenland, director of strategic marketing for National Semiconductor's Power Management Group. "This synchronous buck regulator combines ease of use, online design tool support, a wide input voltage range and innovative constant on-time architecture."
Complex digital loads require fast transient response. National's LM3100 employs a high-performance constant on-time (COT) architecture with a proprietary, patent-pending flywheel current injection control (FCIC) that allows the use of ceramic output capacitors without additional equivalent series resistance (ESR) compensation. Input voltage feed-forward rejects line transients and keeps the switching frequency nearly constant when operating from an unregulated supply.
The LM3100 also features 0.8V, 1.5 percent feedback, adjustable switching frequency up to 1 megaHertz and an asymmetrical power stage tuned for step-down conversion. Company officials said these design features make the LM3100 Simple Switcher buck regulator easy to use and well-suited for a diverse range of loads and applications, including fine-pitch grid arrays, digital sensor processors, digital application-specific integrated circuits, networking, gaming, audio-video, medical and industrial.
The LM3100 includes the following features and benefits:
—Wide Vin range of 4.5V to 36V, ideal for industrial and automotive infotainment
—0.8V, 1.5 percent feedback voltage for next-generation digital cores
—Ultra-fast load transient response of COT FCIC, which requires no external loop compensation, and is simple and agile with fewer filter capacitors
—Adjustable switching frequency up to 1 MHz for smaller footprint
—Vin feed forward, which rejects input transients and ensures constant frequency over a wide input voltage range
—Low external component count, reducing overall system cost and solution size
—Monolithic synchronous MOSFET for improved efficiency at low output voltages
—Soft-start to control in-rush current and prevent output voltage overshoot at application of power
—Output over-voltage protection
—Cycle-by-cycle valley current limit for protection against overload and short-circuit loads
—Thermally enhanced eTSSOP-20 package to reduce junction temperature at maximum load
—Thermal shutdown during overloads
Available now, the LM3100 is priced at $2.50 in 1,000-unit quantities.
