University of California

Yang Lin

Clark T-c Nguyen

Clark Tu-Cuong Nguyen

Bongsang Kim

Wei-Chang Li

A circuit of N micromechanical resonant switches (resoswitches) is presented, which mimics a Dickson charge pump to amplify an input voltage to an output voltage of N plus 1 times the input voltage, while avoiding the diode voltage drop and breakdown voltage limitations of CMOS-based conventional charge pumps. Important aspects of successful charge pumping are: 1) the long cycle lifetime of resonant micromechanical switches, which has been shown to operate 173.9&#xd7;10cycles, is orders of magnitude higher than non-resonant switches; 2) the use of gated-sinusoid drive excitation to allow a charging period independent of resoswitch resonance frequency; and 3) the use of resonance operation to lower required drive and DC-bias voltages to below the supply voltage. This mechanical charge pump obviates the need for custom high voltage CMOS for applications where large voltages are needed such as MEMS-based timing references, thereby allowing the use of virtually any CMOS process.

Micromechanical resonant switches and charge pumps

A modally driven oscillating element periodically contacts one of more electrical contacts, thereby acting as a switch, otherwise known as a resonant switch, or 'resoswitch', with very high Q's, typically above 10000 in air, and higher in vacuum. Due to periodic constrained contacting of the contacts, the bandwidth of the switch is greatly improved. One or more oscillating elements may be vibrationally interconnected with conductive or nonconductive coupling elements, whereby increased bandwidths of such an overall switching system may be achieved. Using the resoswitch, power amplifiers and converters more closely approaching ideal may be implemented. Integrated circuit fabrication techniques may construct the resoswitch with other integrated CMOS elements for highly compact switching devices. Through introduction of specific geometries within the oscillating elements, displacement gains may be made where modal deflections are greatly increased, thereby reducing device drive voltages to 2.5 V or lower.

Growing community of inventors

Albany, CA, United States of America

Yang Lin