| 摘要 |
PURPOSE: A circuit for inputting phase locked data into two phase locked loop chips is provided, which lock two frequencies using one micro processor in a modulator method using a DSP(Digital Signal Processing). CONSTITUTION: According to a phase locked loop control circuit to output signals having different frequencies each other by controlling two phase locked loops, a ROM stores data to control outputs of the two phase locked loops. A DSP outputs a signal to control two different phase locked loops by receiving data of the ROM, a micro controller signal, phasing data and an initialization signal from the micro processor. A latch stores and outputs a signal of the DSP. A divider outputs a clock signal by dividing a signal from a buffer amplification circuit 1, and a FIFO receives 12 bit data information from the divider and the DSP. A digital-analog converter converts a digital output of the FIFO into an analog modulation signal of 100kHz. A synthesizer generates 90MHz signal by synthesizing the outputs of a buffer amplification circuit 2 and the digital-analog converter. An amplifier amplifies an output of the synthesizer, and a band pass filter passes only the 90MHz signal among the amplified signal, and an amplifier amplifies the 90MHz signal.
|
