New Industry Products

Vishay Intros SiP21101/SiP21102 LDO Regulators

July 31, 2005 by Jeff Shepard

Vishay Intertechnology Inc. (Malvern, PA) announced two new 150 mA low-noise, low-dropout (LDO) regulators, the SiP21101 and SiP21102, which are suitable for use in battery-powered equipment such as cell phones, PDAs, pagers, digital cameras, MP3 players, cable and DSL modems, and other noise-sensitive electronics. With a small 2 mm x 2 mm footprint, the SiP21101 and SiP21102 feature a low dropout of 130 mV and a ground current of 110 µA, helping to prolong battery life in low-voltage portable electronic systems. Designed to maintain regulation while delivering 300 mA peak current, the new ICs both feature a fast startup time of 50 µsec. Fifteen fixed-output voltage options ranging from 1.2 V to 5.0 V are available.

An active pull-down circuit is built into the devices to clamp the output voltage when it rises beyond normal regulation, discharging it automatically by connecting the output to ground through a 100 Ω n-channel MOSFET when the device is put in shutdown mode. Reverse battery protection limits the reverse current flow to approximately 1 µA to prevent damage to the IC in the event that a reversed battery is applied at the input.

The SiP21101 provides a quiet voltage source because of an external noise bypass capacitor connected to its BP pin that reduces noise to only 30 µV, a significant benefit for RF applications. The same pin on the SiP21102, which has a noise output of 75 µV, functions as an error flag output that goes low when the output voltage drops four percent below its normal voltage.

Available now in a small, five-pin SC-70 package for most voltage options, in samples and production quantities, the SiP21101 and SiP21102 are priced at $0.40 each in 1,000-piece quantities, with lead times of six to eight weeks for larger orders.