A 65-nm CMOS Temperature-Compensated Mobility-Based Frequency Reference for Wireless Sensor Networks

Abstract

Abstract-For the first time, a temperature-compensated CMOS frequency reference based on the electron mobility in a MOS transistor is presented. Over the temperature range from -55• C to 125• C, its frequency spread is less than ±0.5% after a two-point trim and less than ±2.7% after a one-point trim. These results make it suitable for use in Wireless Sensor Network nodes. Fabricated in a baseline 65-nm CMOS process, the 150 kHz frequency reference occupies 0.2 mm 2 and draws 42.6 µA from a 1.2-V supply at room temperature.

A Sub- $${100\,\hbox {ppm}/{^{\circ }\hbox {C}}}$$ 100 ppm / ∘ C Temperature-Compensated High-Frequency CMOS Relaxation Oscillator

“…Figure 2 shows the effect of temperature variations on V C , which were obtained by using ideal I C and I R with zero TCs and ideal resistor R with TC (R) = 0. According to (10) and (12), g m1 and G M increase with temperature, thus the effective V R is reduced (i.e., the peak voltage of the sawtooth waveform in Fig. 2 decreases as temperature increases), and thus f osc is increased as temperature increases.…”

“…1a, the TC ( f osc ) can be derived from (3) as given by (7). Typically, on-chip capacitors (e.g., metal-insulator-metal or polysiliconpolysilicon capacitors) have very small TCs, compared with those of on-chip resistors (e.g., see Table 1 (1), the TC (G M ), and thus TC ( f osc ), can be derived as given by (10). Therefore, TC ( f osc ) can be minimized by canceling the two terms of TC (R) and TC (g m1 ) in (10).…”

“…Emerging short-range, low-cost, and low-power wireless communication systems, such as wireless sensor and body area networks [1,10,11], have relaxed performance requirements for radio transceivers. These systems have recently prompted research and development of highly stable and accurate integrated oscillators as a replacement of the reliable quartz crystal oscillators.…”

A low power low supply sensitivity current-mode relaxation oscillator

“…Recently, there has been an increasing demand for SoCs in small-size, low-power and low-cost applications, such as battery-operated biomedical devices [1] and wireless sensor networks [2]. As an important component, on-chip oscillators are widely employed in those SoCs for timing reference.…”

Process, voltage and temperature compensation in a 1-MHz 130nm CMOS monolithic clock oscillator with 2.3% accuracy

“…De Smedt, De Wit, Vereecken, and Steyaert (2009) , Lu, Yuan, Der, Ki, and Yue (2013), Sebastiano et al (2011aSebastiano et al ( , 2011b, Ueno, Asai, and Amemiya (2009) reported on-chip clock oscillators with high accuracy, but their accuracy relied on special resistors or trimming and they are not pure PVT compensation on-chip. In Sebastiano et al (2011a), the authors followed the idea of Blauschild (1994), but the compensation was off-chip. An example of carrier-mobilitybased oscillator is found in Sebastiano et al (2011b).…”