Machine-to-machine (M2M) provider Telit Wireless Solutions and analogue semiconductor company SiTime Corporation have combined forces to develop a new wave of ultra-miniature tracking and navigation devices.
SiTime, a California-based company specialising in synchronisation, has combined its SiT15xx oscillators with Telit’s Jupiter SE880 miniature GPS receiver to produce what is claimed to be world’s smallest and lowest power GPS receiver with extended hibernation periods at 15µA while maintaining Snap Start to less than one second.
SiTime’s SiT15xx family of microelectromechanical system (MEMS) silicon oscillators overcomes the limitations of crystal quartz-based devices in several ways. SiTime’s devices offer area savings of 85%, cut power by 50% and are 15 times more reliable, all of which enable smaller, lower power and longer lasting tracking and navigation devices together with Telit’s Jupiter SE880 miniature GPS receiver.
Battery powered electronic devices like trackers and personal navigation systems use hibernation techniques to extend battery life which entail shutting down the functional blocks with the highest current drain and switching them to the lowest power suspend/sleep state whenever possible.
However, during the low-power state, the system’s always-ON 32 kHz Lo-clock continues to draw battery power. The low 750 nA core current and unique power saving features of the 32 kHz SiT15xx family, such as programmable output frequency and output drive swing level, can dramatically lower system power consumption compared with traditional crystal clocks, the companies said.
Additionally, crystal clocks drift over time and over temperature requiring systems to wake up more frequently to correct system clocks and maintain systems in hot start conditions. With ± 100 PPM over the entire industrial temperature range, SiT15xx devices are 2 to 3 times more stable than crystal devices.
This reduces the need for systems to wake up and further lowers power consumption. The SiT15xx family operates from 1.2V to 3.63V for regulated power supplies or from 2.7 to 4.5V for unregulated Li-Ion batteries. SiT15xx oscillators offer the smallest footprint in 1.5x0.8 mm chip-scale package (CSP) and eliminate the need for external capacitors.
Telit’s miniature 4.7x4.7mm LGA (Land Grid Array), SiRFstarIV-based Jupiter SE880 receiver module not only employs leading heterogeneous 3D integration technology, but also provides ways and means for utilizing the latest star products in the fast evolving TCXO and 32kHz technologies.
This enables receiver designs that are best in class in performance and all other dimensions critical for regular or size-constrained GPS applications. Its state of the art RF front-end employs spatially calibrated waveguide-quality radio paths inside the three-dimensional space of its architecture drastically reducing system noises and parasitic impedances characteristic of traditional 2-D RF designs.
Inside, a multi-filter system includes not only the traditional SAW filters typical in GPS receiver designs but also a 2.4 GHz notch-filter capable of nullifying the jamming effects of high-energy radio devices such as Wi-Fi hot-spots, Bluetooth systems, cordless phones, and others, which greatly affect a GPS receiver’s ability to resolve timid satellite signals in the hostile radio environment where they need to operate.
Piyush Sevalia, executive vice president of marketing at SiTime, said: “SiTime has re-invented the timing industry with silicon MEMS timing solutions that overcome the limitations of quartz and dramatically improve customers’ designs with higher performance, lower power and smaller size. Our ultra-stable SiT15xx family of 32 kHz oscillators is extending these benefits to the fast-growing mobile market.
“We are pleased to collaborate with Telit on their low-power GPS modules. SiTime’s 32 kHz oscillators offer 2 to 3 times better stability than quartz oscillators – which allows more precise control of hibernation and standby modes, and greatly improves system power consumption. This is one more example of how SiTime’s MEMS and analogue leadership is making it possible for our customers to deliver unprecedented performance.”
“Wearable technology is an emerging application area in general particularly for geo-location,” said Mike Ueland, senior vice president and general manager of Telit Wireless Solutions North America. “Every square millimeter reduced in footprint on a miniature GPS receiver enables countless new products that could not have been imagined or developed before.”