Voltage-Controlled Delay Line for Precise Phase Tuning of a 10-MHz Clock in Integrated Dual Active Bridge Converters

This paper presents the design, simulations and measurement results of an integrated Voltage-Controlled Delay Line (VCDL) to ensure reliable phase regulation in Dual Active Bridge (DAB) converters. The proposed architecture employs a current-mode delay control mechanism and an internally generated supply voltage to achieve fine phase modulation with minimal duty-cycle distortion of 1.5% for the output clock signal. Simulation and measurement results show excellent agreement, with a maximum deviation of 5% for voltage-to-phase-shift characteristics. An external trimming mechanism compensates for phase shift deviations exceeding 30% of clock period with reliable timing performance across all operating conditions. Moreover, the circuit demonstrates strong robustness against supply voltage variations in the range between 4.5 V - 5.5 V, without affecting phase shift accuracy. These features make the proposed circuit well-suited for integration in high-frequency, closed-loop control systems requiring accurate phase regulation.