Title :
An IC for closed-loop control of a micromotor with an electrostatically levitated rotor
Author :
Alladi, Dinesh J. ; Nagy, Michael L. ; Gaverick, S.L.
Author_Institution :
Cirrus Logic Inc., Austin, TX, USA
Abstract :
A new micromotor structure proposed uses an electrostatic bearing to levitate the rotor. A sampling controller digitally controls five degrees of freedom for levitation by sensing differential capacitances. The controller is compatible with an existing rotation controller and has been implemented in a 1.2-μm, double-poly CMOS process. It uses a low noise circuit to resolve the polarity of charge packets as small as 500 aC (3000 e-) every 1.5 μs
Keywords :
CMOS digital integrated circuits; closed loop systems; digital control; electrostatic motors; machine bearings; machine control; microcontrollers; rotors; 1.2 micron; IC sampling controller; MEMS device; charge packet polarity; closed-loop control; differential capacitance sensing; digital control; double-poly CMOS process; electrostatic bearing; low noise circuit; micromotor; rotor levitation; Capacitance; Digital control; Electrostatic levitation; Geometry; Micromechanical devices; Micromotors; Rotors; Silicon; Stators; Structural discs;
Conference_Titel :
Circuits and Systems, 1999. ISCAS '99. Proceedings of the 1999 IEEE International Symposium on
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-5471-0
DOI :
10.1109/ISCAS.1999.780201
