New 150-mA LDO Voltage Regulators With Low Ground Current, Ultra-Low Noise and Fast Turn-on Save Power and Space in Battery-Powered Electronics

SANTA CLARA, CALIFORNIA - December 14, 2001 - Two new 150-mA low-noise lowdropout (LDO) regulators designed for use in battery-powered equipmentsuch as cell phones, wireless handsets and modems, PDAs, notebooks, pagersand digital cameras were announced today by Siliconix incorporated(NASDAQ: SILI), an 80.4%-owned subsidiary of Vishay Intertechnology (NYSE:VSH).

The Si91841 andSi91843 feature a lowground current of only 110 µAat 150 mA - ideal for low-voltage battery-operated power systems - and anextraordinarily low dropout voltage of 130 mV, prolonging battery life inportable electronics. The devices' ultra-low noise output provides a quietvoltage source, while an external noise bypass capacitor further reducesnoise levels for RF systems and other applications requiring low outputnoise to just 30 µV_(rms).

Designed to maintain regulation while delivering 300-mA peak output current in applications with high surge currents at turn-on, the Si91841 and Si91843 are available in a range of 14 fixed output voltage options from 1.8 V to 5.0 V. Both devices feature 1.5% guaranteed output voltage accuracy, a fast start-up time of 50 µs, and fast transient response of ≤ 30 µs. A built-in active pull-down clamp circuit improves transient response and regulation by actively sinking current from the output if it exceeds the desired regulation voltage. The Si91841 discharges the output during shutdown mode through a 100-Ω n-channel MOSFET, while the Si91843 maintains an open circuit on the output.

Integrated short-circuit and thermal protection ensure reliable operation.Reverse battery protection limits reverse current flow to a 1-µAmaximum shutdown current. When no output is required, an ON/OFF featureallows digital circuitry to shut off the device to save power.

Packaged in a 5-pin SOT23, the Si91841 and Si91843 may be used with low-ESR ceramic capacitors or tantalum capacitors, giving designers a flexible choice of magnetic components.

Samples and production quantities of the Si91841 and Si91843 are available now for most voltage options, with lead times of six to 10 weeks for larger orders.

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.