September 10, 2002 – National Semiconductor Corporation (NYSE:NSM) today announced a series of CMOS power management ICs for low-voltage applications in handsets and other portable devices.
The new DC/DC buck converters provide a highly efficient solution to the handheld industry’s continual challenge to supply low-ripple, precise voltages to processors and power amplifiers while extending battery life in portable devices.
“National leads the industry in innovation for power management IC design and manufacturing,” said John Fairbanks, principle business marketing engineer for National’s Portable Power Systems group. “The top portable device manufacturers trust National to deliver innovative products that keep pace with the growing power demands in phone handsets and other battery-powered devices.”
National’s latest low-voltage offerings include the LM2608, LM2614 and LM2618 magnetic buck DC/DC converters and LM2788 and LM2798 switched capacitor buck converters. They provide precise, efficient, high-density, highly integrated step-down converter solutions in industry-leading miniature packages.
Magnetic Converters
The LM2608, LM2614 and LM2618 are magnetic buck DC/DC converters that offer precise solutions for powering RF and digital baseband applications with up to 95 percent efficiency at +/- 2 percent accuracy. The magnetic converters are the optimal choice when efficiency is of utmost importance. The LM26XX magnetic converters put out up to 400mA, which optimizes them for most cell phone and general-purpose processor applications. Pin selectable output voltages at 1.8V, 1.5V, 1.3V or 1.05V eliminate the need for an external voltage divider. They also allow the system designer to dynamically scale back the operating voltage to reduce the power for low frequency operating modes.
The LM2608 and LM2618 are dual-mode converters optimized for powering low-voltage digital portions of phone handsets. The LM2608 functions in PWM (pulse width modulation) under high current load conditions, but converts to linear mode for light loads with a low operating quiescent current (Iq) of 20 microAmps. Like the LM2608, the LM2618 operates in PWM under high current load conditions. Its second mode is pulse frequency modulation (PFM), efficient for 1 to 50 mA loads encountered in low-level, background processing tasks.
The LM2614 is a flexible part that increases the efficiency of the RF power amplifier (PA), which is one of the largest consumers of power in a cellular handset. The LM2614 allows adaptive voltage scaling for the PA via a simple user application circuit that provides the desired control and transfer functions to position Vout for optimal efficiency.
Switched Capacitor Converters
The LM2788 and LM2798, which require no external inductors, are among the industry’s smallest step-down converters. They efficiently and cost effectively produce a 120mA regulated low-voltage current from input voltages of 2.8V to 5.5V. State-of-the-art fractional gain and gain hopping circuitry provides efficient operation over a wide range of input to output voltage ratios. All three of the available output voltage options (1.5V, 1.8V and 2.0V) can be produced at peak efficiencies in the 80% to 90% range from a 3.3-volt rail. Average efficiencies over 80% can be achieved supplying nominal loads from a Lithium-ion battery over the full range of LiIon voltages. The LM2788/98 switched capacitor converters have a low operating supply current of only 32 microAmps when unloaded, allowing for long battery life in sleep mode. The LM2798 has logic output flags that indicate when input and output voltages are at acceptable levels. The LM2788/98 can be used to power low-voltage microprocessors and other low-voltage circuits in a wide variety of applications, including digital cameras, cell phones, PCs and PC peripherals such as rechargeable Bluetooth™ devices or USB flash storage systems.Packaging
National leads the industry in manufacturing and packaging technologies. The LM26XX magnetic switchers are available in National’s die-sized microSMD 10-bump package. The LM2788/98 switched capacitor converters are in miniature MSOP packages in 8-pin (LM2788) and 10-pin (LM2798) configurations.
Pricing and Availability
All of these new devices are available now. The LM2608, LM2614 and LM2618 are priced at $1.20. The LM2788 is $0.89. The LM2798 is $.99. All prices are for a quantity of 1000 units.
For more information about these buck regulator parts, visit National’s World Wide Web site at http://www.national.com/pf/LM/LM2608.html, http://www.national.com/pf/LM/LM2614.html, http://www.national.com/pf/LM/LM2618.html, http://www.national.com/pf/LM/LM2788.html and http://www.national.com/pf/LM/LM2798.html.
Powering Innovation
National is powering innovation. First in technology, performance and packaging, we supply best-in-class power management solutions for cell phones, personal digital assistants, digital cameras and other handheld, portable electronics. Visit us at power.national.com.
About National Semiconductor
National Semiconductor is the premier analog company driving the information age. Combining real-world analog and state-of-the-art digital technology, the company is focused on the fast growing markets for wireless handsets; displays; information infrastructure, and information appliances. With headquarters in Santa Clara, California, National reported sales of $1.5 billion for its most recent fiscal year and has about 10,000 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.
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