A New Current-mode LC Oscillator with Automatic Amplitude Aalibration

A new circuit structure of current-mode LC oscillator,which is designed for electromagnetic induction sensor with automatic amplitude calibration(AAC) to correct the PCB process dispersion of the coils,is presented. Different from traditional VCO structure,the new one works through current mode,which makes the amplitude calibration easily.The LC tank is integrated in the PCB and the circuit is implemented in a standard 0.35μm CMOS process.It works at 3.3MHz(low frequency) and draws between 0.7 and 1.9 mA from a 5V supply.Consider the amplitude,it can be calibrated within 5mV around 4.19V conservatively.The new design can be used for high frequency application on the result of RF simulation.