Abstract: There is provided a method and circuit for trimming a functional resistor on a thermally isolated micro-platform such that a second functional resistor on the same micro-platform remains substantially untrimmed; a method and circuit for providing and trimming a circuit such that at least two circuit elements of the circuit are subjected to a same operating environment and the operating environment is compensated for by distributing heat generated during operation of the circuit among the two circuit elements; a method and circuit for trimming a functional resistor on a thermally-isolated micro-platform such that a constant temperature distribution is obtained across the functional resistor; and a method and circuit for calculating a temperature coefficient of resistance of a functional resistor.

Abstract: There is described a method and sub-circuit to measure temperature coefficients (coefficient of variation of a measurable parameter of the component), by using a thermally-isolated silicon micro-platform with a mass of mono-crystalline silicon suspended from it. The particular effectiveness of the measurement of temperature coefficient(s) stems from the influence of the mono-crystalline silicon mass in maintaining a substantially uniform temperature throughout the micro-platform. The measurement of temperature coefficient can be an absolute temperature coefficient of one or more components, or can be a relative temperature coefficient of two components, or can be relative temperature coefficients between more than two components.

Abstract: There is provided a method and circuit for trimming a functional resistor on a thermally isolated micro-platform such that a second functional resistor on the same micro-platform remains substantially untrimmed; a method and circuit for providing and trimming a circuit such that at least two circuit elements of the circuit are subjected to a same operating environment and the operating environment is compensated for by distributing heat generated during operation of the circuit among the two circuit elements; a method and circuit for trimming a functional resistor on a thermally-isolated micro-platform such that a constant temperature distribution is obtained across the functional resistor; and a method and circuit for calculating a temperature coefficient of resistance of a functional resistor.

Abstract: A compound resistor is used to compensate for trimming induced shift in temperature coefficient of resistance of a trimmable resistor. The compound resistor is composed of a first and second portion, at least one of the two portions being thermally trimmable, and the parameters for the first and second portion are selected such that the trimming induced shift can be minimized on an overall resistance and temperature coefficient of resistance of the compound resistors by trimming the trimmable resistor. The invention also allows for exploring trimming range available via true thermal trimming without actually trimming out resistor's value of a resistor. The invention also allows design of thermal isolation to minimize or optimize resistance variation of the overall compound resistance.

Abstract: There is described a method and circuit for determining a temperature coefficient of change of a parameter of an electrical component, the method comprising: providing at least one thermally-isolated micro-platform on a substrate; placing an electrical component on the at least one thermally-isolated micro-platform; heating the electrical component; measuring a parameter value of the electrical component at a plurality of temperatures; and determining the temperature coefficient based on the measured parameter values.

Abstract: There are described various methods and circuits for trimming the parameter value of a thermally mutable electrical component in two directions. A sequence of heat pulses is selected as a function of thermal history using an adaptive trimming algorithm, where parameters of the sequence of heat pulses are based on a resulting impact of previous heating pulses. Direction of trimming, trimming increment, and remaining trimming distance can all be used to determine the parameters of succeeding heat pulses, wherein the parameters of the pulses can be, for example, amplitude, duration, and time interval between pulses.

Abstract: Electro-thermal trimming of thermally-trimmable resistors is used to trim one or more of the plurality of resistors in or associated with an analog electric circuit. The TCR of each of a subset of a plurality of electro-thermally-trimmable resistors can be trimmed independently from the resistance in order to adjust the output parameter of an analog electric circuit without changing other parameters that would be affected by a change in resistance.

Abstract: There is described methods and circuits for trimming a temperature coefficient of change of a parameter of at least one electrical component while maintaining a substantially constant parameter value, the method comprising applying a heating cycle to trim said parameter value away from a target parameter value and back to said target parameter value, whereby the temperature coefficient of change is modified after applying said heating cycle.

Abstract: There is provided a method and circuit for trimming a functional resistor on a thermally isolated micro-platform such that a second functional resistor on the same micro-platform remains substantially untrimmed; a method and circuit for providing and trimming a circuit such that at least two circuit elements of the circuit are subjected to a same operating environment and the operating environment is compensated for by distributing heat generated during operation of the circuit among the two circuit elements; a method and circuit for trimming a functional resistor on a thermally-isolated micro-platform such that a constant temperature distribution is obtained across the functional resistor; and a method and circuit for calculating a temperature coefficient of resistance of a functional resistor.

Abstract: There is described a method and sub-circuit to measure temperature coefficients (coefficient of variation of a measurable parameter of the component), by using a thermally-isolated silicon micro-platform with a mass of mono-crystalline silicon suspended from it. The particular effectiveness of the measurement of temperature coefficient(s) stems from the influence of the mono-crystalline silicon mass in maintaining a substantially uniform temperature throughout the micro-platform. The measurement of temperature coefficient can be an absolute temperature coefficient of one or more components, or can be a relative temperature coefficient of two components, or can be relative temperature coefficients between more than two components.

Abstract: There is described a method for designing a circuit having a plurality of thermally mutable electrical components having different power dissipation and noise tolerance requirements, the method comprising: identifying a desired value for said noise tolerance and said power dissipation for each of said plurality of components; selecting a parameter value for each of said plurality of components; and selecting a dimension for each of said plurality of components as a function of said power dissipation and noise tolerance requirements to yield a trimmable range including said parameter value.

Abstract: There is provided a method and circuit for trimming a functional resistor on a thermally isolated micro-platform such that a second functional resistor on the same micro-platform remains substantially untrimmed; a method and circuit for providing and trimming a circuit such that at least two circuit elements of the circuit are subjected to a same operating environment and the operating environment is compensated for by distributing heat generated during operation of the circuit among the two circuit elements; a method and circuit for trimming a functional resistor on a thermally-isolated micro-platform such that a constant temperature distribution is obtained across the functional resistor; and a method and circuit for calculating a temperature coefficient of resistance of a functional resistor.

Abstract: There is provided a method and circuit for trimming a functional resistor on a thermally isolated micro-platform such that a second functional resistor on the same micro-platform remains substantially untrimmed; a method and circuit for providing and trimming a circuit such that at least two circuit elements of the circuit are subjected to a same operating environment and the operating environment is compensated for by distributing heat generated during operation of the circuit among the two circuit elements; a method and circuit for trimming a functional resistor on a thermally-isolated micro-platform such that a constant temperature distribution is obtained across the functional resistor; and a method and circuit for calculating a temperature coefficient of resistance of a functional resistor.

Abstract: This invention addresses a fundamental weakness in currently common microphones, and their applications in feedback for audio speaker systems. This limitation stems from the fundamental difficulties of typical membrane-type microphones in the frequency range 1-100 Hz. The self-noise of membrane-type microphones increases in this range approximately as 1/f, and membrane-type microphones are sensitive to parasitic inertial vibrations, which are usually very important in this frequency range. The removal of these limitations enables the use of such a sensor (APV sensor) for effective feedback in audio speakers, dramatically improving performance in the low-frequency range of 10-100 Hz. Without feedback, typical audio speakers suffer severe attenuation and/or distortion in this range.