Abstract:
To check the programming of a nonvolatile memory cell storing an actual threshold value, the drain terminal of the cell is biased at a constant voltage; the gate terminal is biased at a check voltage; the cell is supplied with a predetermined current to determine a gate-source voltage drop related to the actual threshold value; and the voltage at the source terminal is supplied to an input of an operational amplifier. In an open-loop configuration, the desired threshold value of the set predetermined current is supplied as the check voltage; the amplifier compares the source voltage with the ground; and switching of the amplifier indicates the desired threshold value has been reached. In a closed-loop configuration, the output of the operational amplifier is connected directly to the gate terminal of the cell, and supplies the desired threshold value directly.
Abstract:
A current generator circuit with controllable frequency response has at least one current mirror formed of MOS transistors, being powered through a terminal held at a constant voltage, having an input leg through which a reference current (I1) is driven by a first current generator (G1), and having an output leg for generating, on an output terminal (OUT) of the mirror, a mirrored current (I.sub.out) which is proportional to the reference current (I1). The input leg includes at least a first transistor (M1) which is diode-connected and has a control terminal (Ga1) coupled to a corresponding terminal (Ga2) of a second transistor (M2) included in the output leg by an impedance matching circuit configured to hold the same voltage value at both terminals (Ga1 and Ga2). The impedance matching circuit has an adjustable output impedance, specifically lower in value than the value to be had without this circuit. It functions to regulate the impedance on the control node (Ga2) of the second transistor (M2). The invention is equally applicable to N-channel and P-channel MOS transistors. Advantageously, the reference current can be varied by an external signal which is a function of the output signal, to provide feedback regulating features.
Abstract:
In a memory device equipped with a redundancy circuit comprising at least one redundancy memory register storing a defective address of a defective memory element and an identifying code suitable for identifying a portion of a matrix of memory elements wherein the defective memory element is located, a circuit for transferring redundancy data of a redundancy circuit inside the memory device is provided. The circuit comprises a shared bus of signal lines provided in the memory device to interconnect a plurality of circuit blocks of the memory device and for transferring signals between the circuit blocks. The shared bus can be selectively to the various circuit blocks, and a bus assignment circuit associated to the redundancy circuit is provided for assigning, during a prescribed time interval of a read cycle of the memory device, the shared bus to the redundancy circuit whereby in the prescribed time interval the identifying code stored in the redundancy memory register can be transferred onto the shared bus.
Abstract:
A voltage-controlled oscillator, with high noise rejection of the supply voltage, includes a plurality of delay cells in an odd number N.gtoreq.3, which are connected to form a first ring oscillator and powered by the difference between a supply voltage Vcc and a variable regulating voltage VR. The VCO comprises at least one second ring oscillator formed by a plurality of delay cells in an odd number M.gtoreq.3, at least one of which is also a delay cell of the first oscillator and at least two of which do not belong to the first oscillator. At least one of these two cells is powered by a constant voltage (Vcc), in such a manner that the two oscillators operate at the same frequency and the interaction between the two oscillators introduces a high-frequency negative feedback which has the effect of effectively reducing the noise of the supply voltage Vcc.
Abstract:
The broadcast mode of the different ones set by the international standards for digital audio broadcasting (DAB) according to a coded orthogonal frequency division multiplexing scheme (COEFDM) may be automatically detected in a receiver through a detection routine. Many of the calculation modules required by the automatic mode detection system of the invention are already present in a receiver and can be exploited for performing the digital signal processing that leads to an automatic recognition of the broadcast mode of the station on which the receiver is tuned.
Abstract:
A process for manufacturing a MOS-technology power device chip and package assembly, the MOS-technology power device chip comprises a semiconductor material layer in which a plurality of elementary functional units is integrated, each elementary functional unit contributing a respective fraction to an overall current and including a first doped region of a first conductivity type formed in the semiconductor layer, and a second doped region of a second conductivity type formed inside the first doped region; the package comprises a plurality of pins for the external electrical and mechanical connection; the plurality of elementary functional its is composed of sub-pluralities of elementary functional units, the second doped regions of all the elementary functional units of each sub-plurality being contacted by a same respective metal plate electrically insulated from the metal plates contacting the second doped regions of all the elementary functional units of the other sub-pluralities; each of the metal plates are connected, through a respective bonding wire, to a respective pin of the package.
Abstract:
An integrated operational amplifier with adjustable frequency compensation having a transconductance input stage and an amplifier output stage connected serially together between an input terminal and an output terminal of the operational amplifier. For the purpose of frequency compensation, moreover, a compensation block is connected across the input and the output of the output stage. The compensation block uses a plurality of charge storage elements connected in parallel together and in series with switch block which selects a sub-plurality of said charge storage elements in response to an external signal of the amplifier. The compensation block thereby provides an overall effective capacitance for frequency compensation.
Abstract:
The need of implementing a second local oscillator in addition to the drive oscillator, for timing the different phases of the starting process of a half-bridge or bridge stage driving an external load, such as a fluorescent lamp, is avoided by employing a timing counter to count the number of oscillations produced by the drive oscillator, and a digital-to-analog converter for controlling the frequency of oscillation of the drive oscillator.
Abstract:
Generator of clock pulses having a period selectable between a first period, a second period of greater duration than that of the first period and a third period, with duration imposed by the transitions of a synchronization signal (SYNC) from a first to a second logic level, comprising: a resettable oscillator controlled by a binary selection signal having a first and second logic level, in order to generate periodic pulses having the first or second period depending on the logic level of the said selection signal, the oscillator comprising a pulse extractor triggered by the periodic pulses and by the transitions from first to second logic level of the synchronization signal in order to generate, with each pulse and transition received as input, one of the said periodic clock pulses, acting as reset signal for the oscillator, and a finite state logic machine, having at least two states A, B and inputs for receiving the synchronization signal and the periodic pulses, and generating the selection signal at a first logic level, in state A, and at the second logic level in state B, the machine evolving from state to state as a function of the signals and received as input.
Abstract:
An interface circuit for coupling the output of an integrated circuit designed for a relatively low supply voltage to a circuit designed to operate at a higher supply voltage employs a cascoded architecture and makes use of two purposely derived reference voltages. The circuit comprises a level rising stage, an output buffer stage (off chip driver stage), an overdrive stage for the pull-up device of the output buffer and a drain follower stage, the pull-up element of which is driven by a second output node of the level rising stage and the pull-down element of which is driven by the inverted input data stream.