DESIGN AND FABRICATION OF PHASE – LOCKED LOOP FREQUENCY SYNTHESIZER CIRCUIT

Tan Qiuhong, Zhang Yongwei, Jiang Shaoquan

ABSTRACT: This paper introduces the design and fabrication of phase-locked loop frequency synthesizer circuit based on ADF4351 chip. System master chip selection STM32F103C8T6, power chip selection AMS1117-3.3V, display part of the use of OLED12864 LCD screen, download the chip selection CH340G. The STM32F103C8T6 converts the set frequency value into the value of the register, and then configures the corresponding register in the ADF4351 through the three-wire serial communication. ADF4351 according to the value of the register, control the internal voltage-controlled oscillator to produce the required frequency, and then divided by the output divider, you can set the frequency. While the screen shows the output frequency size. The test output frequency is stable, the amplitude is larger.

Keywords: Frequency synthesizer, loop filter, ADF4351, voltage controlled oscillator.