Single-pole single-throw microelectro-mechanical switch with active off-state control

摘要

A CMOS differential operational amplifier (36) connected to a variable power supply (44) causes the electrodes (14,18) to close and open an electrical circuit based on control voltage (32). When control voltage is zero, increase in supply voltage results in simultaneous application of actuation voltage between two electrodes, for opening electrical circuit. A cantilever beam (16) has electrodes (14,18) and a contact electrode (20). The input terminal of the amplifier are connected to a MOS transistor (34) of the control circuit (30). The amplifier has two outputs connected to the electrodes (14,18). Another MOS transistor (42) is also connected to the supply terminal (38) of the amplifier. When the transistors are closed, an increase in the control voltage results in an actuation voltage being applied differentially between the electrodes closing the electrical circuit.