MEMS Oscillator Plus Tiny GPS Receiver Create Ultra-Mini Tracking Device
A joint effort between Telit and SiTime produced what the companies claim is the smallest and lowest-power GPS receiver with extended hibernation periods at 15 µA and a Snap Start of less than one second. The receiver combines SiTime’s SiT15xx microelectromechanical-system (MEMS) silicon oscillators with Telit’s Jupiter SE880 miniature GPS receiver. The silicon oscillators save space by 85%, cut power by 50%, and are two to three times more stable (±100 ppm over the entire industrial temperature range) than their crystal quartz-based counterparts, says SiTime. Maintaining a 750-nA core current, the 32-kHz SiT15xx devices feature power-saving features such as programmable output frequency and output drive swing level. The oscillators, housed in in 1.5- by 0.8-mm chip-scale packages, operate from 1.2 to 3.63 V for regulated power supplies, or from 2.7 to 4.5 V for unregulated Li-ion batteries. Telit’s 4.7- by 4.7-mm land-grid-array, SiRFstarIV-based Jupiter SE880 receiver module features an RF front-end with spatially calibrated, waveguide-quality radio paths inside a 3D architecture. Its multi-filter system includes traditional SAW filters as well as a 2.4-GHz notch filter that can nullify the jamming effects of high-energy radio devices (e.g., Wi-Fi hotspots, Bluetooth systems).
