Dual-cell structure digitally controlled oscillator with portability for clock generation applications.

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Signal Processing

Background:

• High-performance clock generation is critical for modern digital systems.
• Existing digitally controlled oscillators (DCOs) face limitations in frequency range and timing resolution.
• The need for portable and easily migratable DCO designs is increasing.

Purpose of the Study:

• To present a novel dual-cell structure for a digitally controlled oscillator (DCO).
• To enhance maximum output frequency and extend the controllable range of DCOs.
• To achieve wide output frequency range and high timing resolution simultaneously using a cascaded digitally controlled delay cell.

Main Methods:

• A dual-cell structure and cell-based design for a DCO were developed.
• A cascaded structure was employed for the digitally controlled delay cell.
• The DCO was fabricated using 0.18 µm CMOS technology.

Main Results:

• The DCO chip occupies a core area of 0.003 mm².
• The operational frequency range spans from 169 MHz to 522 MHz.
• The finest delay resolution achieved is 2.2 ps.

Conclusions:

• The proposed dual-cell DCO significantly increases maximum output frequency and extends the controllable range.
• The cascaded digitally controlled delay cell enables both wide frequency range and high timing resolution.
• The DCO's implementation with digital standard cells ensures portability and reduces design time for different processes.