摘要:
A device for increasing the power output of a low-tension operated amplifier which is connected to a standard impedance loudspeaker and is powered at a voltage level which, in the presence of an audio signal, consists of the DC operating voltage for the set and an overlapping variable voltage which is proportional to the audio signal input to the amplifier.Thus, a high dynamic range is afforded for the output signal from the amplifer directed to the loudspeaker.
摘要:
This integrated semiconductor device aims at drastic reduction of the direct secondary breakdown phenomena and has a plurality of side-by-side elementary transistors forming an interdigited structure. To reduce the thermal interaction between the elementary transistors, the latter are spaced apart from one another by a distance approximately equal to the width of one elementary transistor and are driven by current sources. Spacing apart reduces electrothermal interaction. Further, in order to minimize the device area requirements, the space between any two adjacent elementary transistors is made to accommodate drive transistors operating as current sources, or the elementary transistors of the complementary stage where the device forms a class B output stage, the two output transistors whereof are alternatively switched on.
摘要:
A first non-inverting amplifier unit and a second inverting amplifier unit are driven by a single input signal; their outputs are connected across a load, directly and via a series capacitor, respectively. A circuit disables the second amplifier when the input signal is lower than a preset threshold level.
摘要:
A micro-electro-mechanical device formed by a body of semiconductor material having a thickness and defining a mobile part and a fixed part. The mobile part is formed by a mobile platform, supporting arms extending from the mobile platform to the fixed part, and by mobile electrodes fixed to the mobile platform. The fixed part has fixed electrodes facing the mobile electrodes, a first biasing region fixed to the fixed electrodes, a second biasing region fixed to the supporting arms, and an insulation region of insulating material extending through the entire thickness of the body. The insulation region insulates electrically at least one between the first and the second biasing regions from the rest of the fixed part.
摘要:
A micromachined device made of semiconductor material is formed by: a semiconductor body; an intermediate layer set on top of the semiconductor body; and a substrate, set on top of the intermediate layer. A cavity extends in the intermediate layer and is delimited laterally by bottom fixed regions, at the top by the substrate, and at the bottom by the semiconductor body. The bottom fixed regions form fixed electrodes, which extend in the intermediate layer towards the inside of the cavity. An oscillating element is formed in the substrate above the cavity and is separated from top fixed regions through trenches, which extend throughout the thickness of the substrate. The oscillating element is formed by an oscillating platform set above the cavity, and by mobile electrodes, which extend towards the top fixed regions in a staggered way with respect to the fixed electrodes. The fixed electrodes and mobile electrodes are thus comb-fingered in plan view but formed on different levels.
摘要:
A bi-dimensional position sensor that can be advantageously used in the turn system controlled from the steering wheel of a vehicle. The sensor includes a permanent magnet fixed to a control lever so as to move in a plane along first and second directions and to rotate about a third direction orthogonal to the preceding ones. The permanent magnet is movable with respect to an integrated device including a first group of sensor elements arranged spaced along the first direction, a second group of sensor elements arranged spaced along the second direction and a third group of sensor elements detecting the angular position of the permanent magnet. Electronics integrated with the sensor elements generate a code associated with each position which the permanent magnet may assume and generate a control signal corresponding to the desired function.
摘要:
An electrostatic cleaning structure of a hard disk driver is formed by a plurality of concentric conductive regions to which biasing pulse trains are supplied. Each biased conductive region generates an electric field attracting any dielectric particle. The pulse trains supplied to immediately adjacent conductive regions are phase-shifted by a predetermined time and in a direction linked to a desired direction of removal for the electrostatic particles. Voltage pulses sent to each conductive region are delayed with respect to voltage pulses sent to an immediately preceding conductive region in the direction of desired removal, and are advanced with respect the voltage pulses sent to an immediately successive conductive region.
摘要:
A microelectromechanical structure, usable in an optical switch for directing a light beam towards one of two light guide elements, including: a mirror element, rotatably movable; an actuator, which can translate; and a motion conversion assembly, arranged between the mirror element and the actuator. The motion conversion assembly includes a projection integral with the mirror element and elastic engagement elements integral with the actuator and elastically loaded towards the projection. The elastic engagement elements are formed by metal plates fixed to the actuator at one of their ends and engaging the projection with an abutting edge countershaped with respect to the projection.
摘要:
A method for the electrical and/or mechanical interconnection of components of a microelectronic system includes at least one first component and at least one second component to be connected, and at least one local Joule-effect micro-heater is incorporated in one of the first and second components at a respective soldering point therebetween. The method includes supplying electrical energy to the micro-heater to utilize the heat produced therefrom by the Joule effect to solder the first and second components at the respective soldering point.
摘要:
The additional voltage drop across a guard diode against supply polarity inversion in an integrated bridge circuit for driving an external load and employing two high-side NPN power switches driven by two PNP transistors, all monolithically integrated using a junction-type isolation technique, is substantially eliminated by connecting the emitters of the two PNP drive transistors directly to the positive rail, i.e. to the anode of the guard diode. Integrated PNP transistors are per se intrinsically protected against polarity inversion and when so connected permit to reduce the overall voltage drop across the driving bridge circuit. Using a Zener diode as the guard diode and a second Zener diode connected in opposition to the first Zener between the cathode thereof and the negative supply rail an additional spike protection of the circuit's components is implemented.