Patent ID: 8665031

Claim:
An oscillating circuit for determining a resonant frequency of an electro-mechanical oscillating device and for driving the electro-mechanical oscillating device at the determined resonant frequency, the oscillating circuit comprising: a driving circuit configured to receive at least one reference signal and further configured to provide a driving signal related to the at least one reference signal to the electro-mechanical oscillating device; a start up excitation signal generating circuit operably coupled to the electro-mechanical oscillating device, wherein the start up excitation signal generating circuit is configured to selectively provide a start-up excitation signal to the driving circuit, and wherein the start up excitation signal generating circuit is activated upon start-up of the oscillating circuit to drive the electro-mechanical oscillation device, the start-up excitation signal generating circuit including: a pseudo-random noise generator configured to generate the start-up excitation signal from a digital excitation sequence predetermined to be within the bandwidth of resonance of the electro-mechanical oscillating device; and a start-up switch configured to selectively couple the start-up excitation signal to the driving circuit, wherein the driving circuit determines a resonant frequency by measuring a parameter related to the resonant frequency of the electro-mechanical oscillating device.