A voltage controlled oscillator having an oscillation frequency variation minimized in comparison with a power supply voltage variation

摘要

The voltage controlled oscillator includes an oscillator having an output node connected between a potential power supply line and a low potential power supply line and outputting an oscillation signal having a frequency varied in accordance with a voltage difference between the potential power supply line and the low potential power supply line. The nMOS transistor includes a drain connected to a high low potential supply voltage and a source connected to a power supply line to the collector. Since the gate of the nMOS transistor is connected to receive the control signal, the source voltage of the nMOS transistor is determined by the voltage of the control signal and is supplied to the power supply of the oscillator. As a result, . The level converter is connected between the high potential supply voltage and the low potential supply voltage and has an input node connected to the output node of the oscillator and an output terminal outputting the output signal. The level converter converts the amplitude of the oscillation signal to the amplitude of the output signal corresponding to the voltage difference between the high, low potential supply voltage. Therefore, a voltage-controlled oscillator having excellent insensibility to a change in power supply voltage can be realized.;Representative diagram: Figure 2