This paper deals with different approaches to design Phase Locked Loop (PLL) frequency synthesizer. PLL system responds to both frequency and phase of the input signals, automatically raising or lowering the frequency of controlled oscillator until it is matched to the reference in both frequency and phase. The performance of PLL frequency synthesizer is improved by using different Voltage cont...

The high performance of today's digital phase-lock loop makes it the preferred choice for generation of stablee low noisee tunable local oscillators in wireless communications applicationss This paper investigates the design of passive loop filters for Frequency Synthesizers utilizing a Phase-Frequency Detector and a current switch charge pump such as National Semiconductor's PLLatinum TM Serie...

In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequencies are designed and fabricated in 0.5 μm n-well CMOS process. Cadence/Spectre simulations show that the frequency range of the switchable phased-locked loop is between 320 MHz ...

Flying-Adder frequency synthesis architecture is a comparatively new technique of generating fractional frequency derived from reference frequency. The first advantage is that system consists of pure digital circuits. The second advantage is fast response. On the other hand, this synthesizer generates a desired average frequency, which is not spectrally pure. Since its invention, it has been ut...

This work presents an interpolated flying-adder(FA-) based frequency synthesizer. The architecture of an interpolated FA, which uses an interpolated multiplexer (MUX) to replace the multiplexer in conventional flying adder, improves the cycle-to-cycle jitter and root-mean-square (RMS) jitter performance. A multiphase all-digital phase-locked loop (ADPLL) provides steady reference signals for th...

An optimized Direct Digital Frequency Synthesizer (DDFS) design in terms of reduced ROM, high throughput and speed is designed in this paper. DDFS is designed with 200 MHz reference clock frequency and 32 bit FTW for the generation of sine and cosine signal with 16 bit output frequency having frequency resolution of 0.0466 Hz and Phase resolution of 0.0055°. DDFS design is simulated using VHDL ...