A Calibrated Phase/Frequency Detector for Reference Spur Reduction in Charge-Pump PLLs

Author(s):  
C.T. Charles ◽  
D.J. Allstot
Author(s):  
P.N. Metange ◽  
K. B. Khanchandani

<p>This paper presents the analysis and design of high performance phase frequency detector, charge pump and loop filter circuits for phase locked loop in wireless applications. The proposed phase frequency detector (PFD) consumes only 8 µW and utilises small area. Also, at 1.8V voltage supply the maximum operation frequency of the conventional PFD is 500 MHz whereas proposed PFD is 5 GHz. Hence, highly suitable for low power, high speed and low jitter applications.  The differential charge pump uses switches using NMOS and the inverter delays for up and down signals do not generate any offset due to its fully symmetric operation. This configuration doubles the range of output voltage compliance compared to single ended charge pump. Differential stage is less sensitive to the leakage current since leakage current behaves as common mode offset with the dual output stages. All the circuits are implemented using cadence 0.18 μm CMOS Process.</p>


2014 ◽  
Vol 597 ◽  
pp. 515-518
Author(s):  
Shao Hua Chen ◽  
Ming Bo Lin

In this paper, we propose an all-digital, cyclic and synthesizable TDC architecture, which may be used as a core block in ADPLLs to replace the analog block as a phase/frequency detector and a charge pump. Traditional designs of the DVFS scheme for multidomain power management are based on a conventional analog PLL to generate the dynamic voltage and frequency in which the use of a digital TDC eliminates the need for current sources in conventional analog PLLs.


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