Abstract: CMOS reference structures (e.g., voltage, current and resistance structures) are provided that are substantially insensitive to temperature, supply voltages and track fabrication processes. The structures include a V.sub.t -referenced source, a sensor and a summer. The source generates a source voltage and a feed-forward current that may have an error term and the sensor generates a feedback current that has a correction term that substantially offsets the error to stabilize a sum current. In different structure embodiments, voltage, current and resistance references are responsive to the stabilized sum current. The source, sensor and summer are preferably realized with MOSFETs whose channel width-to-length ratios are chosen to enhance the temperature insensitivity of the references.

Abstract: Signal-controlled oscillator structures are provided that are substantially insensitive to temperature, supply voltages and fabrication processes. They include a plurality of time-delay stages that are serially connected in a closed feedback ring and each of the stages includes an amplifier, at least one capacitor and at least one signal-controlled impedance element that couples the capacitor to the amplifier. Accordingly, the frequency of the oscillator is a function of a control signal applied to the impedance elements of the stages. In an oscillator embodiment, each of the amplifiers is a differential pair of transistors, the capacitor comprises first and second capacitors and the signal-controlled impedance element comprises first and second coupling transistors that each couples a respective one of the capacitors to a different side of the differential output.

Abstract: An electric oscillating tool, having particular but not necessarily exclusive utility as an electric toothbrush, for driving a brush head assembly or end effector with a resonant mechanism at high frequencies. The electric toothbrush includes handle housing, an electromagnetic motor mounted in the housing, and a mechanical oscillator acted upon by the motor. One end of the mechanical oscillator extends outwardly through an opening in the handle housing while the other end is attached to the housing inside the chamber. The end effector/brush head assembly attaches to the extending end of the mechanical oscillator. A power source supplies an alternating current drive signal to the motor, in turn causing the armature and the mechanical oscillator to oscillate and drive the brush head assembly.