Novel phase frequency detector circuit

Abstract

The invention discloses a novel phase frequency detector circuit which is mainly composed of a first control module (1), a first logic gate module (2), a second control module (3) and a second logic gate module (4). The novel phase frequency detector circuit is a feedback system and has the characteristic of longitudinal symmetry in circuit implementation, that is, a first control module (1) and a second control module (3) are completely identical in structure, each control module comprises a PMOS (P-channel Metal Oxide Semiconductor) tube and four NMOS (N-channel Metal Oxide Semiconductor) tubes, and the first control module (1) and the second control module (3) are used for respectively controlling two corresponding logic gate modules to generate correct phase frequency detection output; the first logic gate module (2) and the second logic gate module (4) are identical in structure, and each of the first logic gate module (2) and the second logic gate module (4) comprises three PMOS tubes and three NMOS tubes to form an AND gate. Through ingenious circuit design, the problems that a traditional phase frequency detector circuit is large in transistor number, large in occupied chip area, large in power consumption, long in key path delay time and low in phase frequency detection precision are solved.

Description

technical field [0001] The invention belongs to the field of integrated circuit design, and in particular relates to a novel frequency and phase detector circuit. Background technique [0002] A frequency and phase detector is a circuit that compares two input signals and can detect both phase difference and frequency difference. It can be used as a pulse generator. The phase-frequency detector is the key module in the phase-locked loop. Phase-locked loops are common building blocks in integrated circuits. In the transceiver system, the phase-locked loop can be used to generate the local oscillator signal to realize the modulation and demodulation of the signal; in the analog circuit, the phase-locked loop can be used to generate a high-precision clock as the input of the analog-to-digital converter and other components. [0003] With the application of phase-locked loops more and more widely, the requirements for frequency and phase detectors are also getting higher and h...

AI Technical Summary

Problems solved by technology

refer to figure 1 , the traditional frequency and phase detector circuit includes two D flip-flops and an AND gate, at least 38 transistors are required, the number of transistors is large, the chip area is large, and the power consumption is large; and the output signal of the traditional frequency and phase detector circuit The pulse width of QB is about 5 levels of gate delay, the key path delay time is long, and the frequency and phase detection accuracy is low

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