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Semtech Introduces New Synchronous Step-down Power Supply Controller

Low Quiescent Current and Fast Transient Response Support Demands of Battery Operated Portables

Camarillo, California - October 03, 2001

Semtech Corp. (Nasdaq: SMTC), Semtech Corp. (Nasdaq: SMTC), a leading supplier of analog and mixed-signal semiconductors for communications, computers, and industrial equipment, today announced availability of the SC1470 Synchronous Buck Power Supply Controller. Wide input supply range, fast transient response, small size, and high efficiency operation make the device ideal for use in many designs, including notebook chipsets and LCD displays as well as network power supplies and other embedded applications.

Featuring a 4.5V to 25V input supply range, the SC1470 can operate directly from either the battery/AC adapter input of a notebook computer or from a system 5V supply. The output voltage can be programmed within the 0.5V to 5V range, making the device ideal for chipset voltages, graphics core voltages, and other power requirements in microprocessor-based applications. The strong 1amp gate drive easily supports applications with load currents as high as 10 amps.

The SC1470 uses a constant on-time approach to regulation. By eliminating the error amplifier typically found in PWM controllers, the associated time lags are also eliminated, thereby providing extremely fast transient response. Removing the error amplifier also enhances control loop stability, simplifying the design process.

Under steady-state conditions, the SC1470 operates at a fixed frequency. During a load or line change, the frequency changes to accommodate the transient event, with fixed frequency operation resuming once the transient event has passed. Designers can program the operating frequency anywhere within the device's 100kHz to 600kHz range, simply by changing resistors. This feature provides designers with the flexibility to optimize their design for efficiency, output filter size, or position the frequency outside the range of interference with other sensitive circuitry.

The SC1470 provides other attractive design features, including:

• Selectable power-save mode - Obtains efficiencies of higher than 90% at 100mA with power-save enabled.
• RDS(on) current sensing - Improves efficiency and reduces cost by eliminating a sense resistor. More accurate current limit control can be achieved by placing a resistor in the source path of the low-side MOSFET.
• 0.5V to 5V output voltage range - Allows the IC to be implemented in current designs and still be applicable in future designs with a sub-1V requirement.
• Low quiescent current (typically 700uA in operation) - Maximizes battery life.

Other features include: excellent line (0.04% per volt) and load (0.3%) regulation; over-current, over-voltage, and over-temperature protection; under-voltage lockout; and a power good indication that can control downstream circuitry or sequence other power supplies. The SC1470 is designed to operate over the full industrial temperature range of -40°C to +85°C.

Pricing and Availability

Evaluation samples of the SC1470 are available now in TSSOP-14 packaging, with full production units available in November 2001. Pricing begins at $2.65 in production quantities of 1,000 pieces.

About Semtech

Semtech Corporation is a leading supplier of high-quality analog and mixed-signal semiconductor products.  The company is dedicated to providing customers with proprietary solutions and breakthrough technology in power management, protection, advanced communications, human interface, test & measurement, and wireless connectivity products.  Publicly traded since 1967, Semtech is listed on the NASDAQ National Market under the symbol SMTC.  For more information, contact Semtech Corp. at 200 Flynn Road, Camarillo, CA 93012-8790; phone (805) 498-2111; email to info@semtech.com; or visit its web site at www.semtech.com.

Press Contact

Terry Sears, Marketing Communications Manager, Telephone: 805.498.2111