Design of Digital Frequency Sensitive Phase Detector and study its Phase Response

E.N. Ganesh

Abstract

In this paper, a digital frequency sensitive phase detector (PD) with voltage controlled phase response is presented. This scheme is based on classical type flip-flop phase detectors and an improved PD operating on both edges of the input sequence. Phase-to-voltage response characteristic control is accomplished by the additional feedback of the low-pass filter output voltage to reset the control pin input. In this paper, we have presented a simulated frequency sensitive phase detector circuit and showed an improved phase-voltage response with control over its characteristics. The output signal of the phase detector is controlled by a digital signal and thus precisely controls its characteristics. The Phase detector operational status has been tested on both falling and rising edges and is proven to operate within the detected range. Here, the signal slope control ranges from + to - π. But other phase detectors have control on one of the input signal's edges, either on the falling edge or on the rising edge, but here it is designed on both sides so control is possible. Two types of circuits are considered for the study. The first type only works on up and half edge controls while the second has both up and down edge controls and thus can have full or fine control