New Compact 150-mA LDO Voltage Regulators Feature Low Ground Current, Low Noise, and Fast Turn-On

SANTA CLARA, CALIFORNIA - December 21, 2001 - Siliconix incorporated (NASDAQ: SILI), an 80.4%-owned subsidiary of Vishay Intertechnology (NYSE: VSH) has announced the launch of the Si91842 and Si91844, two new 150-mA low-noise low dropout (LDO) regulators featuring exceptionally low dropout and ground current in a compact package. The new devices are intended for use in battery-powered systems, including cell phones, wireless handsets and modems, PDAs, notebooks, pagers and digital cameras.

Available in a range of 14 fixed output voltage options from 1.8 V to 5.0V, the Si91842 and Si91844 are designed tomaintain regulation whiledelivering 300-mA peak output current in applications with high surge currents at turn-on. Aimed at low-voltage battery-operated systems, both devices feature low ground current of only 110 µA at 150 mA, as wellas an extremely low drop out voltage of 130 mV, enabling prolonged battery life in portable electronics. The output voltage is monitored by internal circuitry to provide an error flag signal when the output is within 5% of nominal.

The Si91842 and Si91844 feature 1.5% guaranteedoutput voltage accuracy,a fast turn-on time of 50µs maximum, 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 Si91842 discharges the output during shutdown mode through a 100-Ω n-channel MOSFET, while the Si91844 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-µA maximum current. When no output is required, the shutdown feature allows digital circuitry to turn off the device, reducing current consumption to1 µA and further extending battery life.

The Si91842 and Si91844 are packaged in a 5-pin SOT23 and may be used with low-ESR ceramic capacitors or tantalum capacitors, offering designers flexibility in choosing magnetic components.

Samples and production quantities of the Si91842 and Si91844 are available now for most voltage options, with lead times of 6 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.