A Fast Startup CMOS Crystal Oscillator Using Two-Step Injection

Megawer, Karim M.; Pal, Nilanjan; Elkholy, Ahmed; Ahmed, Mostafa Gamal; Khashaba, Amr; Hanumolu, Pavan Kumar

doi:10.1109/jssc.2019.2936296

Cited by 19 publications

(11 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where L and C are motional inductance and capacitance, respectively. A quartz crystal is represented by an equivalent circuit in which a coil with inductance L, capacitor with inductance C, and resistor with a motional resistance R are connected in series, while a shunt capacitor with capacitance C 0 is connected in parallel [7][8][9]34,37]. A complex impedance (Z) of one quartz crystal is given as…”

Section: Impedance Of One Two and Three Quartz Crystals In Parallelmentioning

confidence: 99%

“…An important advantage of the switching method is also a high temperature dynamic stability and an extended temperature region of operation (0-50 • C). The switching mode operation of the oscillator enables a high stability of oscillation at a very low sensing capacity and reduces the start-up time from ∼ =20 min to ∼ =1 min [33,37,38]. The method is simple with a low number of elements that are required in the circuit.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multiple Quartz Crystals Connected in Parallel for High-Resolution Sensing of Capacitance Changes

Matko

2022

Sensors

View full text Add to dashboard Cite

We present a new highly sensitive, low-value capacitance sensor method that uses multiple quartz crystals connected in parallel inside the oscillator. In the experimental setup, the measured (sensible) reactance (capacitance) is connected in parallel to the total shunt capacitance of the quartz crystals, oscillating in the oscillator. Because AT-cut crystals have a certain nonlinear frequency–temperature dependence, we use the switching mode method, by which we achieve a temperature compensation of the AT-cut crystals’ frequency–temperature characteristics in the temperature range between 0–50 °C. The oscillator switching method also compensates for any other influences on the frequency of the oscillator, such as ageing of the crystals and oscillator elements, supply voltage fluctuations, and other parasitic impedances in the oscillating circuit. Subsequently using two 50-ms-delayed switches between the measuring and reference capacitors, the experimental error in measuring the capacitance is lowered for measurements under a dynamic temperature variation in the range of 0–50 °C. The experimental results show that the switching method, which includes a multiple quartz connection and high-temperature compensation improvement of the quartz crystals’ characteristics, enables a sub-aF resolution. It converts capacitance changes in the range 10 zF–200fF to frequencies in the range 4 kHz–100 kHz.

show abstract

Section: Impedance Of One Two and Three Quartz Crystals In Parallelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multiple Quartz Crystals Connected in Parallel for High-Resolution Sensing of Capacitance Changes

Matko

2022

Sensors

View full text Add to dashboard Cite

show abstract

“…where The phase noise and operation frequency of crystal oscillators can be selected based on the available values. The designs in [27]- [29] provide a phase noise in the range of −153 to −158 dBc/Hz at 100-kHz offset for operation frequencies from 40 MHz to 54 MHz while drawing less than 0.2 mW. On the other hand, Vectron's OX-305 100-MHz crystal oscillator exhibits a phase noise of −178 dBc/Hz but draws 1.8 W [30].…”

Section: Analysis Frameworkmentioning

confidence: 99%

Jitter-Power Trade-Offs in PLLs

Razavi

2021

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

As new applications impose jitter values in the range of a few tens of femtoseconds, the design of phase-locked loops faces daunting challenges. This paper derives basic relations between the tolerable jitter and the power consumption, predicting severe issues as jitters below 10 fs are sought. The results are also applied to the sampling clocks in analog-to-digital converters and suggest that clock generation may consume a greater power than the converter itself.

show abstract

“…Crystal oscillators (XO) are commonly used as a clock source for RTC due to their better frequency stability [8,9,10,11]. However, the power consumption of XO is very high, generally in the range of hundreds of nW to uW [12,13,14,15,16], which cannot satisfy the power budget of ultra-low power systems (less than 10 nW) [17,18,19]. Therefore, an ultra-low power XO is particularly demanded.…”

Section: Introductionmentioning

confidence: 99%

A 8.83nW, 0.14ppm/℃ crystal oscillator using duty-cycling automatic amplitude control

Wang

Ren

et al. 2021

IEICE Electron. Express

View full text Add to dashboard Cite

This paper presents an ultra-low power 32.768 kHz crystal oscillator circuit for the real-time clock (RTC) generation. A negative feedback amplitude control loop is employed to reduce the oscillation amplitude and the energy loss of the crystal. To further reduce power consumption, the inverting amplifier is powered on periodically by a dutycycling control pulse, which reduces the static power of the amplifier significantly. Trading off among power consumption, area and design complexity for generating a precise duty cycle pulse, the output square wave of the crystal oscillator circuit is used as the control pulse. The circuit is designed in 55-nm CMOS process with an area of 0.04 mm 2 . It shows a power consumption of 8.83nW which cuts the power consumption by 37% comparing with the circuit without pulse control. The proposed circuit achieves a great temperature stability of 0.14 ppm/℃ from -40 ℃ to 100 ℃ and a power supply sensitivity of 30.5 ppm/V over supply voltage of 0.5-0.8 V.

show abstract

A Fast Startup CMOS Crystal Oscillator Using Two-Step Injection

Cited by 19 publications

References 21 publications

Multiple Quartz Crystals Connected in Parallel for High-Resolution Sensing of Capacitance Changes

Multiple Quartz Crystals Connected in Parallel for High-Resolution Sensing of Capacitance Changes

Jitter-Power Trade-Offs in PLLs

A 8.83nW, 0.14ppm/℃ crystal oscillator using duty-cycling automatic amplitude control

Contact Info

Product

Resources

About