Research on low-power signal source for micromachined resonant sensor

To meet demands for low power and low distortion of micromachined resonant sensor, this paper presents a method to improve present direct digital synthesizer ( DDS ) technology, replacing current zero order holding approximation method to polyline approximation method to reduce the distortion. A theoretical formula in timedomain was calculated, describing the relationship between the number of discrete points and the total harmonic distortion(THD), and confirming the feasibility of this method by MATLAB simulation and circuit realization. This proposed design reduces the demand of system clock but remaining the spectral purity of signal. Moreover, it can be an important theoretical reference of achievement of low power dissipation.