Vishay's New TrenchFET® Gen II Power MOSFETs for Synchronous Buck Converters Offer FOM of 83 and Gate Charge Ratio of 0.515

Values Are 13.5% and 35.6% Lower Than Next-Best SO-8 Devices

SANTA CLARA, CALIFORNIA — December 5, 2003 — Two new devices that bring the ultra-low on-resistance of high-density TrenchFET® Gen II technology to Q_g/PWM-optimized MOSFETs were announced today by Siliconix incorporated (NASDAQ: SILI), an 80.4%-owned subsidiary of Vishay Intertechnology, Inc. (NYSE: VSH).

Compared with the next-best SO-8 devices on the market, the new Si4336DY (LITTLE FOOT® SO-8) and Si7336DP (PowerPAK® SO-8) offer a 13.5% better on-resistance-times-gate charge product of 83 mΩnC, which is the key figure of merit used by designers to select power MOSFETs for synchronous buck converter applications. The ratio of gate-to-drain and gate-to-source charges, which further impacts efficiency, has been improved by 35.6%.

Used as the low-side MOSFET in computer synchronous buck converters, or for fixed-telecom synchronous rectification or point-of-load converters, the Si4336DY and Si7336DP provide reduced switching and conduction losses, or higher current operation with the same efficiency, at frequencies up to 1 MHz.

When paired with two WFET^TM power MOSFET devices on the high side of a synchronous buck converter, two Si4336DY MOSFETs on the low side yield a 1.0% improvement in efficiency over the next-best competitive SO-8 pair. This higher efficiency translates directly into benefits including longer battery life in portable systems, cooler operation, and the ability to add features and functionality requiring higher levels of current.

Both devices are designed for operation at up to 1 MHz and feature a typical rDS(on) of 2.6 mΩ (V_GS=10 V) and typical gate charge of 32 nC (V_GS=4.5). A high threshold voltage combines with the devices' extremely low Q_GD/Q_GS ratio to offer substantial shoot-thru protection and add efficiency by providing good margin for noise and voltage spikes. The Si7336DP's PowerPAK packaging further enhances performance with increased thermal conductivity, current handling, and power dissipation capabilities.

The new Si4336DY and Si7336DP are 100% R_g-tested, minimizing the effect of device variation and ensuring that devices will perform to minimum and maximum specifications in high-frequency applications.

Samples and production quantities of the Si4336DY and Si7336DP are available now, with lead times of 10 to 12 weeks for larger orders.

Siliconix is a leading manufacturer of power MOSFETs, power ICs, analog switches, and multiplexers for computers, cell phones, fixed communications networks, automobiles, and other consumer and industrial electronic systems. With 2002 worldwide sales of $372.9 million, the Company's facilities include a Class 1 wafer fab dedicated to the manufacture of power products in Santa Clara, California, and an affiliated Class 1 wafer fab located in Itzehoe, Germany. The Company's products are also fabricated by subcontractors in Japan, Germany, China, and Taiwan. Assembly and test facilities include a company-owned facility in Taiwan, a joint venture in Shanghai, China, and subcontractors in the Philippines, China, Taiwan, Israel, and the United States.

Vishay Intertechnology, Inc., a Fortune 1,000 Company listed on the NYSE (VSH), is one of the world's largest manufacturers of discrete semiconductors (diodes, rectifiers, transistors, and optoelectronics and selected ICs) and passive electronic components (resistors, capacitors, inductors, sensors, and transducers). These components are used in virtually all types of electronic devices and equipment, in the industrial, computing, automotive, consumer, telecommunications, military, aerospace, and medical markets. Its product innovations, successful acquisition strategy, and ability to provide "one-stop shop" service have made Vishay a global industry leader. Vishay can be found on the Internet at http://www.vishay.com.

LITTLE FOOT, TrenchFET and PowerPAK are registered trademarks and WFET is a trademark of Siliconix incorporated.