VOLTAGE ADJUSTMENT OSCILLATOR IMPROVING PHASE NOISE

摘要

PURPOSE: A voltage adjustment oscillator improving phase noise is provided to enhance PSRR(Power Supply Rejection Ratio) and to minimize the phase noise in output signal of voltage adjustment oscillator, by decreasing the effect caused by the phase noise in source voltage terminal(VDD) to the voltage adjustment oscillator. CONSTITUTION: A voltage adjustment oscillator improving phase noise comprises a voltage-current convertor(21) and a voltage adjustment oscillator cell unit(100). The voltage-current convertor(21) converts an output signal(VLO) from loop filter(not shown) of phase locked loop to a linear current signal. The voltage adjustment oscillator cell unit(100) includes a reference voltage controller(100A) and an amplification controller(100B). The reference voltage controller(100A) controls the effect of noise signal which is in the voltage adjustment oscillator. The amplification controller(100B) is controlled by the output signal of the voltage-current convertor(21), amplifies a non-inverting input signal(Vin+) and an inverting input signal(Vin-) and outputs a positive output signal and a negative output signal.