Measurement apparatus, for generating a first output signal indicative of a measurand, comprises: a first oscillator circuit and a second oscillator circuit, each oscillator circuit being arranged to generate a respective oscillating output signal and comprising at least a respective first component having a property determining a respective output frequency of the respective oscillating output signal; a sensor for sensing said measurand, the sensor comprising said first component of the first oscillator circuit, said property of said first component of the first oscillator circuit being dependent upon said measurand; and circuitry arranged to receive said oscillating output signals and generate said first output signal, said first output signal being indicative of a number of cycles of one of the first and second oscillating output signals in a time period determined by a period of the other of said first and second oscillating output signals.

Disclosed is a method for detecting a value which represents the temperature of a vibrating element of an ultrasonic transducer. The ultrasonic transducer has a resonant frequency (f.sub.r). The method comprises the steps of operating the ultrasonic transducer with an electric measuring signal at a measuring frequency (f.sub.m) which is above the resonant frequency, and of detecting the absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (f.sub.m) and, building thereon, ascertaining the desired value, which is to represent the temperature of a vibrating element of an ultrasonic transducer, as a function of the detected absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (f.sub.m).

A temperature and humidity sensor includes a substrate, a first electrode provided on the substrate, a linear second electrode at least part of which is so provided as to extend along the first electrode, and a moisture sensitive film provided between the part of the second electrode extending along the first electrode and the first electrode. The second electrode has a section that is formed in a spiral shape when viewed from above so as to form an inductor. With this, a precise oscillation circuit can be configured so that a temperature-humidity sensor small in size and capable of being easily manufactured can be provided.

A temperature sensor circuits includes a temperature sensing module, a current generator, a current controlled oscillator, and a counter. The temperature sensing module is sensitive to temperature changes. The current generator respectively generates a positive temperature coefficient current positively related to temperature and a negative temperature coefficient current negatively related to temperature according to the temperature sensed by the temperature induction module. The current controlled oscillator oscillates according to the positive and the negative temperature coefficient currents respectively and outputs a positive and negative temperature coefficient oscillation signals. The counter receives a clock signal and calculates a first period accumulation number of the negative temperature coefficient oscillation signal and a second period accumulation number of the positive temperature coefficient oscillation signal in the same number of clock periods respectively, and acquires a temperature value based on the period accumulation numbers.

An arrangement for temperature measurement at high-voltage potential is disclosed. The energy for measuring the temperature of an optical current transformer is provided by a single photodiode. The photodiode is supplied by light emitted by a light source and guided to the photodiode via an optical waveguide.

A calibration method of a temperature sensor is provided. The temperature sensor having a current source and a ring oscillator generating a square pulse signal with a temperature-dependent square pulse frequency. The acquisition of a first square pulse frequency measurement at a first temperature from the square pulse signal forms a first measurement point. A second square pulse frequency measurement at a second temperature from the second square pulse signal forms a second measurement point. The determination of the relation data being representative of an affine relation between square pulse frequency measurements and temperatures. The affine relation being defined by a used proportionality coefficient modified with respect to a measured proportionality coefficient of a measured affine relation linking the first measurement point and the second measurement point.

Reference center circuitry for a metrology system is disclosed. In one embodiment, the circuitry includes a reference sensor having a topology and characteristics identical to a number of sensors throughout an IC. The both the reference sensor and the sensors on the IC may be used to perform voltage and temperature measurements. The reference sensor may receive a voltage from a precision voltage supply, and may be used as a sensor to provide a basis for calibrating the other sensors, as well. Thereafter, temperature readings obtained from the other sensors may be correlated to the readings obtained by the reference sensor for enhanced accuracy. The reference center circuitry also includes analog process monitoring circuitry, which may be coupled to some, if not all of the transistors implemented on an IC.

The present invention provides a semiconductor device and a measurement method that enables high precision measurement of temperature or humidity or the like over a wide range. A semiconductor device of the present invention determines which is faster out of a reference oscillation and a thermistor oscillation, and using the faster oscillation as a reference, measures a count value based on the other oscillation. Moreover, the count based on the faster oscillation is employed as a reference value, and a count value based on the other oscillation when the reference value is taken as a measurement value. A frequency ratio is computed based on the reference value and the measurement value, and based on the computed frequency ratio, a table expressing correspondence relationships between frequency ratio and temperature is referred to and a temperature acquired.

Various implementations described herein are directed to a method that acquires operating frequencies for a first set of ring oscillators disposed in a first integrated circuit, determines one or more first coefficients and a first constant for each ring oscillator in the first set, and determines a correlation between each of the first coefficients and the first constant. Also, the method may acquire a single operating frequency for each of a second set of ring oscillators in a second integrated circuit at a single pre-determined temperature so as to determine a second constant, predict one or more second coefficients for each ring oscillator in the second set based on the second constant and the correlation, and derive a temperature dependence based on the single operating frequency using the one or more second coefficients and the second constant for each of the second set of ring oscillators.

Disclosed are a temperature measurement circuit and method. The circuit includes a first temperature sensing circuit, a second temperature sensing circuit and a data processing unit. The first temperature sensing circuit is configured to generate a first measurement signal for characterizing a temperature based on an inputted first current signal, a magnitude of the first current signal being correlated to temperature. The second temperature sensing circuit is configured to generate a second measurement signal for characterizing the temperature based on an inputted second current signal, the second current signal being independent of temperature. The data processing unit is configured to determine a current temperature based on a first characteristic parameter corresponding to the first measurement signal and a second characteristic parameter corresponding to the second measurement signal.