摘要:
A varactor has a gate region, first and second biasing regions of N+ type embedded in a well, and first and second extraction regions of P+ type, forming a pair of PN junctions with the well. The PN junctions are inversely biased and extract charge accumulating in the well, below the gate region, when the gate region is biased to a lower voltage than a predetermined threshold value.
摘要:
An operational amplifier, of a type which comprises a differential cell transconductor input stage (2) incorporating a current mirror (5) provided with a pair of degenerative resistors (R9,R10) and a gain stage (7), driven directly by a transistor (Q12) of said mirror (5), has each degenerative resistor (R9,R10) formed within an epitaxial well wherewith a parasitic diode (D1,D2) is associated. Each diode (D1,D2) is connected in parallel with its corresponding resistor (R9,R10) to prevent the transistor (Q12) which drives the gain stage (7) from becoming saturated.
摘要:
An improved planarity when forming contact plugs by a blanket CVD deposition of a metallic matrix layer followed by etchback is achieved by performing a first etchback step to expose the surface of the dielectric material underlying the filling metal layer, while masking the top of the metal plugs with resist caps. The resist caps are formed using a mask derived by field inversion and enlargement from the actual contact mask used for defining the contact areas. With the resist caps covering the contact plugs, the filling metallic material is overetched to eliminate residues along with discontinuities from the planarity of the surface, while shielding the top of the plugs from the overetch. The masked overetch is preferably conducted under conditions of reduced anisotropy and increased selectivity in respect to the first etchback step.
摘要:
The process comprises the steps of forming, on top of a semiconductor material wafer, a holed mask having a lattice structure and comprising a plurality of openings each having a substantially square shape and a side with an inclination of 45° with respect to the flat of the wafer; carrying out an anisotropic etch in TMAH of the wafer, using said holed mask, thus forming a cavity, the cross section of which has the shape of an upside-down isosceles trapezium; and carrying out a chemical vapor deposition using TEOS, thus forming a TEOS layer which completely closes the openings of the holed mask and defines a diaphragm overlying the cavity and on which a suspended integrated structure can subsequently be manufactured.
摘要:
A low noise, high thermal stability attenuator of the integratable type is disclosed. The attenuator comprises a fixed network of resistive elements, having a plurality of outputs each at a different attenuation level, and a switched amplifier receiving at its input such different attenuation outputs, as well as a control signal which specifies which of the amplifier inputs is to be output. Advantageously, this attenuator may be implemented in several stages, each having different attenuation ranges or steps.
摘要:
A substrate insulation device includes power supply terminals which are connected to a terminal of an active integrated element which has, with respect to a substrate on which it is defined, at least one reverse-biased junction.
摘要:
A monolithically integrable high-efficiency control circuit for the switching of transistors includes a first transistor whose base terminal is connected to a source of switching signals. A second transistor whose base is connected to a current generator, drives a third transistor which connected in series with the first transistor such that the first and third transistors are connected between two terminals of a supply voltage generator. The emitter terminal of the third transistor forms an output terminal of the control circuit and is connected to the collector terminal of the first transistor by means of a parallel connected diode and a resistor combination. The circuit also includes a fourth transistor, whose base terminal is connected through a resistor to the base terminal of the third transistor and whose collector and emitter terminals are respectively connected to the base terminal of the second transistor and to the collector terminal of the first transistor.
摘要:
A monolithic integrated voltage regulator consists of a multiplicity of regulator circuits connected in parallel to one another. These circuits have different dropouts and the voltage established across each set of output terminals is held at a predetermined constant value by means of a regulator circuit having its feedback circuits connected thereto. The predetermined value of the voltage across one set of output terminals is deliberately selected to be more or less elevated according to whether the dropout of its associated regulator circuit is more or less elevated.
摘要:
Device for limiting the working voltage for mechanical switches in telephony includes terminals for connection to a telephone line, a connection and power supply branch for a control circuit extending from a first terminal, the branch having a first switch, the cathode terminal of a first Zener diode and the source terminal of a first MOSFET transistor being connected to the output terminal of the first switch, the gate terminal of the first MOSFET transistor being connected, through the anode terminal of the Zener diode, to the first terminal. The current absorbed by the device may be adjusted.
摘要:
An amplifier stage with variable gain dependent on the anode voltage is interposed between a ramp generator having constant amplitude ramp output voltage and the vertical deflection stage in such a manner as to vary the input voltage of said vertical deflection stage in accordance with anode voltage variations. In such a manner the vertical deflection current varies correspondingly.