Silicon Resonator Based 3.2 $\mu$W Real Time Clock With $\pm$10 ppm Frequency Accuracy

Mobility-based Time References for Wireless Sensor Networks

“…• C. However, it is believed that such temperature coefficients are highly reproducible [51], thanks to the high purity and low defect density of the silicon employed for CMOS manufacturing, similarly to what happens in TD-based references (see section 3.5.2). The temperature variations could then be compensated using the appropriate temperature compensation scheme.…”

“…• C temperature range after a three-point temperature calibration with power consumption of a few microwatts [51] and a ±30 ppm inaccuracy over the temperature range from -40…”

A resistor-based temperature sensor for a real time clock with ±2ppm frequency stability

“…This usually involves scaling the oscillator's output frequency in a temperature-dependent manner with the help of a fractional-N division or multiplication scheme [1][2][3][4]. The temperature sensor must then have high accuracy and resolution so as not to compromise the frequency stability and jitter of the compensated output signal [1].…”

“…Recent works [1][2][3], indicate that resistor-based temperature sensors can achieve high resolution in an energy efficient manner, which makes them well suited for RTCs. Their main drawback is that they require multi-point calibration in order to compensate for the non-linear temperature dependence and spread of on-chip resistors.…”

“…Their main drawback is that they require multi-point calibration in order to compensate for the non-linear temperature dependence and spread of on-chip resistors. In the context of RTCs, however, this is allowed, since it is required to accurately compensate for the non-linear temperature dependence of typical quartz-crystal and MEMS oscillators [1][2][3][4].…”