Analog signals picked up by sensors are oversampled and converted locally for example into streams of 1-bit digital words and, without any previous formatting are transmitted on transmission channels to a central station. The central station includes a storage and a combining circuit for combining and weighting directly these 1-bit words, as well as a filter for reconstituting, from the combinations, high-resolution digital words. A preferred application is combining of acoustic or seismic signa...

A high speed data acquisition system which acquires an analog signal, converts it to digital data, and compresses the large volume of accumulated data into a format that can be handled in a microcomputer environment. The data acquisition system of the present invention can rapidly and continuously acquire and process large volumes of data. Included is an averaging circuit which allows the present invention to efficiently process and store large amounts of data uninterruptedly. The present invent...

An analog compensation circuit for providing process/voltage/temperature (PVT) bias compensation signals for input/output (I/O) circuitry within an integrated circuit includes a first current source coupled to a first node. A first load coupled to the first current source and a second node provides a first reference voltage. A voltage divider coupled between the first and second nodes provides a current source bias voltage to the first current source. A differential amplifier generates a first b...

A multi-symbol analysis process compensates for inter-symbol interference in communication signals. The multi-symbol analysis process determines a digital value for a symbol represented by a selected symbol period by correlating a digitized sample within the selected symbol period with a sum of weighted signal components. The sum of weighted signal components includes contributions from the selected symbol period and symbols from a number of other symbol periods that occur before and after the s...

An input circuit for a field device for communication with bidirectional signals superposed on an analog signal, the input circuit being part of a current loop, supplies the field device with energy and simultaneously carries an analog current signal for prescribing a reference value. The field device is connected to an actuator that is suitable for achieving the reference value, and the input circuit has a voltage limiter, a shunt resistor and an inductance connected in series between its input...

An A/D conversion system comprises an A/D converter, a mode selection section for periodically selecting a conversion mode and a standby mode, and a control section for controlling the A/D converter based on the respective modes. The control section breaks the current path for the A/D converter during a standby mode. The duration of the standby mode can be specified from outside the system for power saving.

A successive approximation analog/digital ("A/D") converter that converts an analog input voltage to a digital value for output in a manner enabling a reduction in power consumption. The A/D converter includes a comparator that outputs a referencing result signal by comparing an analog input voltage against a reference voltage. A D/A converter outputs the reference voltage to a comparator in correspondence to a digital voltage signal. A successive approximation register outputs the digital volta...

A monostable circuit of a voltage-to-frequency converter supplies feedback pulses to balance the input signal to a first integrator. These same pulses are supplied to a second integrator where they are compared with reference pulses from a crystal-controlled clock. Any drift in the pulse-width of the feedback pulses is corrected by a control signal applied to the monostable circuit by the second integrator to vary its quasi-stable period appropriately. Thus the precision of the converter is impr...

Method and apparatus for enabling simultaneous storage of multiple images and/or digital data on a storage tube target, and for selectively retrieving such information.

In a microcomputer provided with a CPU which processes digital signals under control of program instructions, and a converter which converts between analog and digital signals, the operation of the converter is controlled to improve reliability and increase CPU efficiency. In response to a control output from the CPU a conversion control circuit passes an operation stop signal to the CPU during a limited period of conversion in which, for example, conversion accuracy is significantly influenced ...