Micropower 2 MHz CMOS frequency reference for capacitive sensor applications

Impulse sensitivity function-based phase noise study for low-power source-coupled CMOS multivibrators

“…In a similar way to the ISF method, these simulators consider a LTV system to obtain the noise power spectral density. To the best of authors' knowledge, the circuits under consideration in this paper are the first multivibrators for which the ISF-based phase noise results have been published [11][12][13], and they are further expanded in this paper. At first glance the procedure of the ISF method seems to be time-consuming, but it can be automated to a great extent, for example by using a combination of EldoRF and Matlab, after which it is quite fast and convenient to use.…”

“…Additionally, based on the simulations the drain clamping with diode-connected PMOS devices (M7-M8) is utilized to improve the overall oscillation frequency stability over the process, voltage, and temperature (PVT) variations. The simulated I-V characteristics of the active load with and without the drain clamping were presented in [12]. With the equally sized devices (M5-M8) used in this implementation the effect of the diode-connected devices can clearly be seen until the larger tail currents.…”

“…In this paper, an illustrative 10-step procedure for applying the ISFbased phase noise study to CMOS oscillators is described, after which it is used for the two implemented frequency references. In comparison to the prior publications [11][12][13], the presentation is extended by providing new simulation and measurement results, together with a more detailed phase noise study. The rest of the paper is organized as follows: Sects.…”

A 3 μW, 2 MHz CMOS frequency reference for capacitive sensor applications

“…In our absolute temperature) current generator, if the MOS transistors case, this optimization has been carried out using symmetrical M10-M13 operate in the subthreshold region. In this case, the loads that are more linear than pure current source loads [3]. output current is [5] Simulations predict that the oscillation frequency varies about Fig.…”

“…Before showing The frequency reference circuit considered in this paper the measurement results, the circuit is briefly described and the is a part of a low-power interface for a micromechanical theory related to the optimization of the frequency stability and capacitive sensor. The interface consists of a front-end circuit the phase noise, partially presented in [3], is described more that converts the capacitive signal to voltage, an A/D converter extensively. that converts the analog signal to digital domain, a clock generator that provides all the required clock signals, and a II.…”