Abstract:
A device for the comparison of two resistors is based upon analog information carried by currents. The device includes a measurement circuit for extracting the currents from the two resistors to be compared, and copies the currents to a parallel analog-digital converter that carries out the division of the extracted currents. The device converts the ratio of the extracted currents into a digital code that is the image of the ratio of the two resistors. The ratio is constantly re-updated as a function of environmental parameters of the circuit, such as the operating temperature. Also disclosed is a system for correcting the value of integrated compensated resistors. The system implements a device of this kind that does not use a reference voltage generator.
Abstract:
An integrated circuit on a silicon substrate includes at least one polysilicon line and at least one antistatic contact connecting the polysilicon line to the silicon substrate. The antistatic contact includes a thin oxide layer between the polysilicon line and the silicon substrate. The thin oxide layer is of a sufficiently small thickness so that a current flows across it by the tunnel effect when the polysilicon line is brought, relatively to the substrate, to a voltage greater or less than determined thresholds.
Abstract:
A read-only memory formed of cells, each of which includes, between a selection line and a bit line, the series connection of a memory element and of a selection MOS transistor with a gate connected to a read control line. The memory elements of blank cells are P-channel MOS transistors and the memory elements of programmed cells are uniformly N-type doped semiconductor regions.
Abstract:
A receiver of a frequency-modulated signal is provided. The receiver includes a frequency-transposition unit for lowering the frequency of the frequency-modulated signal, and a digital demodulator for regenerating a digital signal from the frequency-transposed signal. The frequency-transposition unit includes a local oscillator for generating a local oscillator signal used in lowering the frequency of the frequency-modulated signal. The frequency-transposed signal is sampled in the digital demodulator at the rate of a sampling signal, and the sampling signal is generated by the local oscillator of the frequency-transposition unit. In a preferred embodiment, the local oscillator includes at least one frequency-divider circuit that delivers the sampling signal. Also provided is a method for regenerating a digital signal from a frequency-modulated signal.
Abstract:
A differential amplifier may include a first stage including a first transistor and a second transistor having the same polarity and assembled to constitute a differential amplifier. The first stage may be supplied by first and second mirror current sources. The differential amplifier may further include a common mode control circuit, which may include two inputs receiving a reference voltage VCM and a common mode voltage controlling the first and second mirror current sources, respectively. The differential amplifier may further include a Miller gain stage having inputs and for a setting gain-band product. The differential amplifier may further include an unlocking circuit, inserted between the common mode voltage and the Miller gain stage inputs, to cause the Miller gain stage to conduct on circuit start-up.
Abstract:
The vertical insulated gate transistor includes, on a semiconductor substrate, a vertical pillar incorporating one of the source and drain regions at the top, a gate dielectric layer situated on the flanks of the pillar and on the top surface of the substrate, and a semiconductor gate resting on the gate dielectric layer. The other of the source and drain regions is in the bottom part of the pillar PIL and the insulated gate includes an isolated external portion 15 resting on the flanks of the pillar and an isolated internal portion 14 situated inside the pillar between the source and drain regions. The isolated internal portion is separated laterally from the isolated external portion by two connecting semiconductor regions PL1, PL2 extending between the source and drain regions, and forming two very fine pillars.
Abstract:
A microprocessor comprises a central processing unit having an arithmetic and logic unit with two inputs and one input fed-back to one of the inputs through a data path. The arithmetic and logic unit performs arithmetic and logic operations on binary words temporarily stored within registers in the central processing unit. The central processing unit further includes a shift unit in the data path of the arithmetic and logic unit for performing operations to shift bits in the binary words applied thereto. A selection circuit selects a shift operation to be performed. An inverting circuit inverts the ordering of the bits in the binary words applied thereto, which are in the data path of the arithmetic and logic unit, and a selection circuit selects the inversion operation when the latter is required.
Abstract:
A structure of protection of an area of a semiconductor wafer including a lightly-doped substrate of a first conductivity type against high-frequency noise likely to be injected from components formed in the upper portion of a second area of the wafer. The structure includes a very heavily-doped wall of the first conductivity type having substantially the depth of the upper portion. The wall is divided into segments, each of which is connected to a ground plane.
Abstract:
A generator includes an oscillator for producing a clock signal from N logic signals representing an N-bit control number, with N being an integer greater than 1. The oscillator has Nnull1 components. The N most significant components are each assigned a place value i ranging from 1 to N, and a least significant component provides the clock signal. At least one component with a place value i greater than 1 includes first and second arms. The first arm includes a cell and a first switch connected in series, and the second arm includes 1null21 cells and a second switch connected in series. Each cell includes an odd number of inverters.
Abstract:
A modulation/demodulation device capable of operating with several types of modulation using different carrier frequencies may include a modulator which modulates at least one signal by a signal of a predetermined duration and representative of a binary information supplied by a microprocessor. The device may also include a demodulator which demodulates the modulated signals arriving from a remote site. This may be done by determining the type of modulation of the received signals and their carrier frequency (or frequencies), supplying signals from an analysis of the signals received according to the determined type of modulation, and detecting the signals of determined duration representative of binary information to make them accessible to the microprocessor.