On the surface, oscillator design using quartz crystals might seem straight forward, especially considering the maturity of this technology. However, there are a myriad of design parameters to consider in order to match the crystal to the oscillator circuit. Among these parameters are crystal motional impedance and oscillator negative resistance (a measure of oscillator gain), resonant mode, and drive level. Additionally load capacitance must be considered for parallel resonant mode crystals and the total load capacitance must also include PCB parasitic capacitance as well as integrated capacitance which may be included in the oscillator circuit. All of these parameters must be carefully considered to ensure reliable start up and operation of the circuit. Because an oscillator circuit requires close matching of the resonator to the oscillator circuit, crystal vendors cannot guarantee startup of the crystal. By contrast, oscillators are a completely integrated solution and the oscillator manufacturer matches the quartz resonator to the oscillator circuit. Start-up is therefore guaranteed by SiTime. In short, oscillators are a "Plug-'n-Play" solution that simplifies system design.