POWER GENERATING CIRCUIT, FREQUENCY GENERATING CIRCUIT AND FREQUENCY CONTROL SYSTEM

摘要

A frequency control system includes a power generating circuit and a frequency generating circuit. The power generating circuit includes an up transistor circuit, a down transistor circuit and a capacitor for generating a stable voltage. The frequency generating circuit includes a digital-to-analog converter (DAC), a current source/sink circuit, a voltage-controlled oscillator (VCO) and a digital controller. The DAC receives the stable voltage as a power, the current source/sink circuit receives an analog signal from the DAC, the VCO receives a control voltage from the current source/sink circuit, and the digital controller receives a frequency signal from the VCO and a reference signal, according to which a digital signal is generated and fed to the DAC.

主权项

1. A frequency control system, comprising:
a power generating circuit including an up transistor circuit, a down transistor circuit and a capacitor, the up transistor circuit and the down transistor circuit being connected in series and having a node situated therebetween, the capacitor being electrically coupled between the node and ground, a stable voltage being generated at the node; and a frequency generating circuit including:
a digital-to-analog converter (DAC) receiving the stable voltage as a power, the DAC outputting an analog signal;a current source/sink circuit receiving the analog signal and outputting a control voltage;a voltage-controlled oscillator (VCO) receiving the control voltage and according generating a frequency signal; anda digital controller receiving the frequency signal and a reference signal, according to which a digital signal is generated and fed to an input end of the DAC.