US 2003/0140698 A1 · High voltage drive circuitry aligned with MEMS array

Abstract

Pulse-width modulation (PWM) control and drive circuitry particularly applicable to an array of electrostatic actuators formed in a micro electromechanical system (MEMS), such as used for optical switching. The high-voltage portion may be incorporated in an integrated circuit having drive cells vertically aligned with the MEMS elements. A control cell associated with each actuator includes a register selectively stored with a desired pulse width. A clocked counter distributes its outputs to all control cells. When the counter matches the register, a polarity signal corresponding to a drive clock is latched and controls the voltage applied to the electrostatic cell. The MEMS element may be a tiltable plate supported in its middle by a torsion beam. Complementary binary signals may drive two capacitors formed across the axis of the beam. The register and comparison logic for each cell may be formed by a content addressable memory.

Claims17

Dependent claims

A system including an array of electrically actuated mechanical elements, comprising:

a plurality of electrically controlled actuators arranged in an array and each including at least a first mechanical element with an electrical connection thereto for driving a movement of said first mechanical element relative to a second mechanical element;
a plurality of control circuits associated with respective ones of electrically controlled actuators and connected to respective ones of said electrical connections;
wherein said plurality of control circuits comprise a low-voltage digital circuit section powered by a low-voltage power bus conveying a low voltage;
and
wherein each of said control circuits further comprises a high-voltage circuit section powered by a high-voltage power bus conveying a high voltage at least four times said low voltage;
and
wherein said plurality of actuators are implemented in one level of a bonded structure and wherein said high-voltage circuits are implemented in at least one first integrated circuit in a second level of said bonded structure, the corresponding actuators and high-voltage circuits being vertically aligned in said bonded structure.

4 more elements

Dependencies are inferred from the claim text.

High voltage drive circuitry aligned with MEMS array

Life of this patent

High voltage drive circuitry aligned with MEMS array

Life of this patent

Abstract

Claims17