DCXO family reduces number of components

According to MSC, whereas conventional VCXOs require an external voltage to control the frequency, SiTime's DCXO family of products enable users to digitally control the output frequency. Therefore, a pull range from ±25 parts per million (ppm) to ±1600ppm is achieved and the frequency resolution is 1 part per billion. The DCXOs are said to provide superior pull range linearity of less than 0.01% which is 1000 times better than conventional quartz crystal VCXOs. Unlike traditional VCXOs designs, external d/a converters are not required with the use of DCXOs, resulting in a reduction of the number of components needed for the circuitry. The DCXOs come in three industry standard package sizes (3225, 5032 and 7050) and can optionally be operated with a supply voltage of 1.8, 2.5 to 3.3V. The first version, the SiT3907, is provided with LVCMOS outputs. Versions with differential outputs should come onto the market in the course of the next year.