A multi-band fast-locking delay-locked loop with jitter-bounded feature.

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Signal Processing

Background:

• Delay-locked loops (DLLs) are crucial for clock synchronization in high-speed digital systems.
• Traditional DLLs can suffer from long locking times and output jitter, limiting their application range.
• The need for faster, more stable clocking solutions persists in modern electronics.

Purpose of the Study:

• To present a novel fast-locking delay-locked loop (DLL) architecture.
• To incorporate a jitter-bounded feature for improved clock signal integrity.
• To enhance flexibility and efficiency for wideband applications through a frequency multiplier.

Main Methods:

• Implemented a fast-locking mechanism using a frequency estimator and programmable voltage circuit.
• Employed two phase-frequency detectors and a tunable delay for jitter bounding.
• Developed a compact frequency multiplier with reduced active devices.

Main Results:

• Achieved a minimum lock time of six clock cycles.
• Demonstrated jitter bounding between two reference inputs.
• The DLL operates from 200-400 MHz, and the multiplier from 1-2 GHz.
• Implemented in 0.18-μm CMOS technology with an active area of 0.34 × 0.41 mm².
• Measured power dissipation of 31.5 mW at 1.8 V.

Conclusions:

• The proposed DLL offers rapid locking and controlled jitter, suitable for high-performance applications.
• The integrated frequency multiplier enhances flexibility for wideband clock generation.
• This design provides an efficient and compact solution for clock synchronization challenges.