Digital sensors design based on universal frequency sensors interfacing IC

Low-Cost QCM Sensor System for Screening Semen Samples

“…In PBS, the two-sample Allan variance for the oscillator has been calculated to be 3 × 10 −7 which is comparable to the results reported for a 2 MHz oscillator in water by Rodriguez-Pardo et al [9] although our value is greater than they report for a 9 MHz QCM. A UFDC-1 universal frequency to digital converter [10] was used as a low-cost replacement for the Agilent frequency counter. The UFDC-1 is a 28 pin single-chip programmable two-channel frequency-todigital converter, operating over the frequency range 0.05 Hz to 7.5 MHz; this range can be extended to 120 MHz with prescaling although this results in an accuracy reduction.…”

The design of high precision double buffer MEMS acceleration seismometer

“…(1) It contains a tightly coupled with the ground coccygeal vertebra (1), MEMS acceleration detector chip(2), the output line (4) and connect the chip and the coccygeal vertebra close shell (3).In seismic exploration, the seismic wave with different stratum reflection to the surface of the ground coupled coccygeal vertebra in the form of vibration signal to MEMS acceleration detector chip [4].As shown in fig2, when the vibration signal reaches the detector chip, quality body (a) the displacement controlled by displacement detector (c) perceive and adjust the electromotive force feedback capacitance change (b), make its produce a balancing force, force quality body keep zero position [1].Capacitance variation depends on the strength of vibration signal and electromotive force variation depends on the capacitance variation, therefore, the change of the electromotive force curve on real-time tracking vibration signal intensity change curve, this is the working principle of the MEMS acceleration detector. It is can be seen that detector chip system is mainly composed of three parts: MEMS sensor acquisition module, A/D conversion module and the signal processing module cache.…”

A low-power Read-Out Circuit and low-cost assembly of nanosensors onto a 0.13 μm CMOS Micro-for-Nano chip

“…In [10], [11], the author proposes to renounce to the standard AD conversion and suggests, as a new IEEE standard, the use of low-complexity low-power architecture based on quasidigital output signals to encode analog quantities. The technique achieves good results both for low resistance [12] and high resistance [13] read-out.…”