Abstract:
The operation of externally connected output power transistors of a class AB amplifier is controlled without employing any external sensing resistance of the output current by driving an externally connected power transistor through a level shifting buffer and employing a limiting network composed of an integrated transistor driven by the output of a signal amplifying stage and a resistance connected in series with its drain. The buffer stage shifts the level of the driving signal of the external power transistor by a value equal to the threshold voltage of the integrated transistor of the limiting network thus ensuring the turn-off of the external power transistor under quiescent conditions.
Abstract:
A non-volatile memory cell of the type which includes at least one floating gate transistor and which is realized over a semiconductor substrate includes a source region, and a drain region, separated by a channel region which is overlaid by a thin layer of gate oxide. The gate oxide isolates a floating gate region from the substrate. The floating gate region is coupled to a control gate terminal. The floating gate region of the memory cell develops a first potential barrier between the semiconductor substrate and the gate oxide layer, and a second different potential barrier between the floating gate region and the gate oxide.
Abstract:
A circuit for shifting the voltage level of a digital signal, comprising a first pair of transistors of a first polarity, which are connected to a high-voltage line, and a second pair of transistors of a second polarity, which are connected to a ground line; the first and second pairs of transistors are connected to each other by means of the drain terminals of the respective transistors; an input voltage is applied to the gate terminals of the first pair of transistors. The circuit further includes a secondary circuit for leveling the gate voltages of the transistors of the first and second pairs, which is connected between the first and second pairs of transistors and whereto at least one reference voltage is applied. The circuit also includes an output stage, whose output is a voltage which is shifted in level with respect to the input voltage. The secondary circuit limits the gate-source voltage value of the first pair of transistors to a value which is independent of the voltage value of the high-voltage line, so as to prevent damage to the first pair of transistors.
Abstract:
A method for reducing the RAM requirement for temporarily storing a stream of data blocks in a coding/decoding system of information transferable by blocks, includes the steps of: compressing and coding the data by blocks through a tree search vector quantization (TSVQ); storing TSVQ compressed and coded data in the RAM; and decoding and decompressing in a subsequent reading of the data stored in the RAM the coded and compressed data, thereby reconstituting the stream of digital data blocks. The method may include fixing a certain scanning path of each data block of the stream to be decomposed into vectors of preestablished dimensions; coding the first vector of the scanning of a certain block of data in an unmodified manner; generating a replica vector of the last coded vector and calculating a prediction error vector; quantizing according to a binary search in a table of read-only quantized vectors the prediction error, by coding its address in the table; and repeating several of the steps for all the vectors of the scanning of each input data block.
Abstract:
A self-protected, low emission electronic device for driving a warning horn includes a coil powered from a battery through a control push-button adapted for operation by a user and included in an electric connection between a terminal of the coil and the battery. The device includes a protective circuit portion connected between the battery and the warning horn. The protective circuit portion includes a bridge structure of power components. At least a pair of the power components are MOS power transistors of which one is driven by a charge pump.
Abstract:
A charge pump comprises a plurality of stages connected in series, an input terminal of the charge pump being connected to a voltage supply and an output terminal of the charge pump providing an output voltage higher than the voltage supply. Each stage comprises unidirectional current flow MOS transistor means connected between a stage input terminal and a stage output terminal allowing current to flow only from said stage input terminal to said stage output terminal, and a first capacitor with one plate connected to said stage output terminal and another plate driven by a respective first digital signal periodically switching between ground and said voltage supply. The unidirectional current flow MOS transistor means of the stages have independent bulk electrodes, and a bias voltage generator circuit is provided for biasing the bulk electrodes of said unidirectional current flow MOS transistor means at respective bulk potentials which become progressively higher going from the stages proximate to said input terminal to the stages proximate to said output terminal of the charge pump.
Abstract:
A suspension arm (125) for a head (120) of a disk storage device comprises at least one wall (225, 230) substantially perpendicular to the disk (105) and having a portion (238, 239) which is deformable parallel to a plane extending through a longitudinal axis (235) of the suspension arm (125) and perpendicular to the at least one wall (225, 230), and piezoelectric member (240, 255) which can deform the portion (238, 239) in order correspondingly to move the head (120), the piezoelectric member (240-255) being fixed to the portion (238, 239) of the at least one wall (225, 230).
Abstract:
A CMOS output stage for providing stable quiescent current. The output stage includes a circuit that relates the quiescent current to the channel geometry of a power NMOS transistor and of an NMOS reference transistor of a reference current source. This configuration removes the dependency of the quiescent current on a power PMOS transistor used in the CMOS output stage, the threshold voltage of which may drift over time under high current and voltage operation, and adversely affects quiescent current stability.
Abstract:
System for decoding code words in the EFM-PLUS and/or EFM format in which an enumeration block makes it possible to associate in a one-to-one manner with each of the code words a numerical value from a practically continuous set of numerical values. The numerical value, possibly summed with an offset value, by an address generator, addresses a read-only memory in which are stored information codes, each of which is associated, as decoded information, with one of the code words.
Abstract:
An electronic device for performing convolution operations comprises shift registers for receiving binary input values representative of an original matrix, synapses for storing weights correlated with a mask matrix, and neurons for outputting a binary result dependent on the sum of the binary values weighted by the synapses. Each synapse has a conductance correlated with the weight stored and dependent upon the binary input value. Each neuron generates the binary result in dependence on the total conductance of the corresponding synapses.