| IP개요 |
A nanoresonator can be applied as a bio/chemical sensor by changing the mass of the nanoresonator, and the mass change can be interpreted in the frequency domain. In this paper, we present an open-loop nanoresonator integrated circuit for motional resistance sensing. The circuit determines the frequency characteristics of a nanoresonator, such as quality factor (Q-factor) and resonant frequency, and detects minute resistance changes of the nanoresonator that result in changes in Q-factor or resonant frequency. The proposed nanoresonator integrated circuit is implemented using an open-loop system, and to characterize the open-loop frequency response of the nanoresonator, the IC includes a voltage-controlled oscillator (VCO), a transimpedance amplifier (TIA), and a 16-bit delta-sigma analog-to-digital converter (ADC). For the compensation of the parasitic components that cause the distortions of the phase and magnitude response, a shunt-capacitance cancelling amplifier is used to cancel the effect of the shunt-parasitic capacitance of the nanoresonator. The simulated target nanoresonator is modeled by the Butterworth–Van Dyke equivalent circuit model with a resonant frequency of 10 MHz. The proposed nanoresonator integrated circuit is fabricated using a standard 0.18-μm complementary metal oxide semiconductor (CMOS) process. The simulated resistive sensitivity of the integrated circuit is 5.1 mV/kΩ. |
