A novel switching-linear hybrid dynamic regulator architecture with dual-supply low dropout regulators (LDOs) is presented in this paper. This architecture leverages the intrinsic dual supplies to extend the operating range of the LDOs. Furthermore, it increases the thermo-optic tuning efficiency by reducing the LDO dropout voltage through dynamic supply modulation. This architecture is suitable for large-scale thermooptic tuning in silicon photonics. The efficiency improvement is particularly effective when tracking signals of several adjacent channels are close to each other, e.g., wavelength tuning of a microring array. The principle of this architecture is general and can be implemented using different switching converters and LDOs. A specific design with extensive post-layout simulation results is used to verify the effectiveness of our architecture. Implemented in a 130 nm CMOS process, this design can simultaneously regulate eight output channels with an output swing of 0.8 Vpp. Its peak efficiency when driving 100 ohms loads is 92% at 1 V output, and the dynamic efficiency is around 86% when tracking 50 kHz sinusoidal signals. To the best of our knowledge, this is the first time that dynamic supply modulation has been applied to the thermo-optic tuning of silicon photonic devices.

A novel switching-linear hybrid dynamic regulator with dual-supply LDOs for thermo-optical tuning is presented in this brief. Compared with conventional designs, the proposed design leverages the intrinsic dual supplies to extend the operating range of the LDOs, and increases the thermo-optical tuning efficiency by reducing the dropout of the LDOs through dynamic voltage tracking. It can simultaneously regulate eight output channels and track 0.8 Vpp sinusoidal waveforms at different frequencies. Significant efficiency improvement of the proposed design is achieved for envelope signals with a small difference, which is common in thermo-optical tuning. Implemented in 130 nm CMOS process, the proposed design has a total chip area of 0.675 mm2. The proposed design achieves a conversion efficiency of 88% at 1 V output driving a 200 ohms load. Its dynamic efficiency is about 80% when tracking 50 kHz sinusoidal signals.