Ultra-low power boost DC-DC converter with integrated MEMS resonator

Complementary metal-oxide-semiconductor micro-electromechanical system (CMOS MEMS) resonators provide considerable advantages in size, cost, and power consumption over their crystal-based counterparts. However, the need for external high bias-voltage to drive the MEMS structure has limited the application of CMOS MEMS in portable electronic applications. This paper proposes an ultra-low power boost DC-DC converter with integrated MEMS resonator. The proposed DC-DC converter and MEMS resonator are integrated into a single chip, and the high bias-voltage required for the MEMS resonator is self-provided. The substantial reduction in the size of the resulting device as well as its low power requirements make it ideal for portable applications. A working prototype of the device was fabricated using a UMC 0.18-μm 60-V bipolar-CMOS-DMOS with a MEMS post-process. Measurement results show that the power dissipation of the boost DC-DC converter is less than 15 μW under various input voltages. Comparisons of high bias-voltage from an external supply with an internal DC-DC converter demonstrate the performance of the design. A preserved reset signal at a different clock frequency also verifies the resistance of the proposed design to process variation.