A family of Stratum 3-compliant, silicon MEMs clocks to replace OCXOs and TCXOs are available from SiTime. The SiT5301 and SiT5302 are targeted at telecomms and networking infrastructure such as SONET and synchronous Ethernet-based core and edge routers, wireless basestations, IP timing and smart grid applications. The SiT5301 operates from one to 60MHz and the SiT5302 operates from 60 to 220MHz. Both meet or exceed Telcordia GR1244 Stratum 3 frequency stability specifications for stringent timing applications. They have ±0.1PPM frequency stability over the commercial temperature range of 0 to 70°C and less that ±0.37PPM 24hour holdover stability. They also have ±4.6PPM frequency stability over 20 years. Offering a 60% reduction in size, compared to any other Stratum 3 TCXO and 10 times smaller than an OCXO, the devices are available in a 2520-compatible package, making it, according to the company, the industry's smallest ±100PPB oscillators. The family is also available in 3225, 5032 and 7050 packages. The wide frequency range of one to 220MHz with six digits of accuracy allows designers to program custom frequencies. Unlike quartz, the SiT530x oscillators have no activity dips, which enable a more stable reference clock and superior system performance over temperature. The MEMS clocks have an operating voltage of 2.5 to 3.5V.
