Abstract —An aIgoritbmic analog-to-digital conversion technique is de-scribed which is capable of achieving high-resolution conversion without the use of matched capacitors in an MOS technology. The exact integral multiplication of the signal required by the conversion is realized through an algorithmic circuit method which involves charge summing with an MOS integrator and exchange of capacitors. A first-order cancellation of the charge injection effect from MOS transistor switches is attained with a combination of differential circuit implementation and an optimum timing scheme. An experimental prototype has been fabricated with a standard 5 wm n-well CMOS process. It achieves 12 bit resolution at a sampling rate of 8 kHz. The anafog chip area measures 2400 mils2. c I.

Abstract—Controlling the charge, rather than the voltage, on a parallel-plate, electrostatic actuator theoretically permits stable operation for all deflections. Practically, we show that, using charge control, the maximum stable deflection is limited by 1) charge pull-in, in which the actuator snaps due to the presence of parasitic capacitance and 2) tip-in, in which the rotation mode becomes unstable. This work presents a circuit that controls the amount of charge on a parallel-plate, electrostatic actuator. This circuit reduces the sensitivity to parasitic capacitance, so that tip-in is the limiting instability. A small-signal model of the actuator is developed and used to determine the circuit bandwidth and gain requirements for stable deflections. Four different parallel-plate actuators have been designed and tested to verify the charge control technique as well as to verify charge pull-in, tip-in, and the bandwidth requirements. One design travels 83% of the gap before tip-in. Another design can only travel 20 % of the gap before tip-in, regardless of whether voltage control or charge control is used. [972] Index Terms—Capacitance, charge transfer, dynamics, electrostatic actuators, extended travel, pull-in, rotation.

Reduction of the power dissipation associated with high speed sampling and quantization is a major problem in many applications, including portable video devices such as camcorders, personal communication devices such as wireless LAN transceivers,