Design of Observer-Controller Digital Phase-Locked Loop Using Kalman Filter

Digital PLL is a fundamental construction block for Bluetooth Low Energy (BLE) systems and several other wireless technologies like applications of Internet of Things (IoT), clock generation, recovery, and reconstruction of data. It is also used for ultra-low power operations and numerous digital signal processing techniques. The proposed Digital PLL is base on the loop filter that is observer-controlled, which helps to filter out entire additive noise and the output is improved in the terms of phase noise and transient time response. The main drawback of the previous PLLs is current transreceiver noise that modifies the overall phase noise output of the system is overcome by the new technique known as oscillator pulling technique. Here the output can be separate out without modifying the general performance of phase noise. The observer filter is fundamentally a second-order time-varying system having fundamental gain value. The proposed Digital PLL has been simulated using 0.35 μm CMOS technology. The proposed DPLL is having lesser phase jitter, high operating frequency, and less complexity of the circuit. The designed digital phase-locked loop is 1.5–3 times faster that of the conventional one.