PORTLAND, Ore. — A maker of MEMS timing chips is taking aim at a new market: voltage-controlled crystal oscillators (VCXO).

Most timing chips are designed to remain steady, but VCXOs tune their precise frequency in response to data stream variations. SiTime Corp. (Sunnyvale, Calif.) is claiming to have a smaller solution called a voltage-controlled MEMS oscillator (VCMO).

The current VCXO market includes chips used in set-top boxes, consumer and networked video, modems, data acquisition equipment and for instrumentation. They make up a $364 million market, according to an ABI Research survey. For comparison, the entire timing chip market is over $5 billion.

SiTime's said its the frequency of its VCMO can be adjusted by a few percent in order to lock onto the slightly varying timing of signals in video and other communications data streams. SiTime also claims its VCMO is smaller than VCXOs, which are typically enclosed in 3- by 3-mm packages. SiTime's VCMO, the SiT3701, measures just 2.5 mm by 2 mm

SiTime stacked its MEMS die atop an ASIC housing its programmable phase-locked loop, which can vary output frequency of the 1- to 110-MHz oscillator within four pull ranges: +/-30, 60, 120 or 240 parts per million.

Output frequency and pull ranges are programmed by SiTime 24 hours after receiving orders for samples, followed by volume shipments within two weeks.