Ring-Based Direct Injection-Locked Frequency Divider in Display Technology

This letter presents the first RF frequency divider on glass to demonstrate the feasibility of system on display (SoD). The frequency divider is developed in 1P2M 3 mum low-temperature polycrystalline silicon (LTPS) thin-film transistor technology. The core cell of the LTPS direct injection-locked frequency divider is the single stage ring oscillator. The additional cross-coupled transistor pair increases the phase shift of the ring oscillator to meet the oscillation condition. The maximum locking range of the LTPS frequency divider is 2 MHz, and it can be operated from 120 Hz to 8 MHz with frequency tuning. Operated at 10 V, the frequency divider consumes 1.8 mW of power. The area of the frequency divider circuitry is 2.13 times 2.6 mm.