A micromechanical resonant charge pump

Abstract

A circuit of micromechanical resonant switches (a.k.a., resoswitches) has been demonstrated that mimics the topology of a conventional single stage Dickson charge pump (cf. Figure 1) to boost 1V from a DC power supply to 2V while avoiding the diode voltage drop and breakdown voltage limitations of CMOS-based conventional charge pumps. The keys to successful charge pumping are 1) the long cycle lifetime of resonant micromechanical switches, which at 173 trillion cycles (so far), is orders of magnitude higher than non-resonant ones; 2) the use of gated-sinusoid excitation to allow a charging period independent of resoswitch resonance frequency; and 3) the use of resonance operation to lower the needed drive and dc-bias voltages to below the supply voltage. This mechanical charge pump now obviates the need for custom high voltage CMOS for applications where large voltages are needed, e.g., MEMS-based timing references, thereby allowing the use of virtually any CMOS process.