Showing papers by "International Rectifier published in 1989"
Patent•
28 Aug 1989TL;DR: In this article, a high power MOSFET is disclosed in which a plurality of hexagonal base regions formed in the surface of a chip receive respective hexagonal annular source regions.
Abstract: A high power MOSFET is disclosed in which a plurality of hexagonal base regions formed in the surface of a chip receive respective hexagonal annular source regions. The base regions are relatively shallow and of relatively low conductivity material. A central portion of each of the base regions reaches the upper surface of the wafer and contacts a sheet source electrode which also contacts the source regions. The central regions of the base elements which contact the source electrode are of higher conductivity than the main base portion for a distance extending just below the depth of the source regions. The base regions are formed by ion implantation through a gate oxide which is exposed by a window in an overlying polysilicon layer. After ion implantation and driving of the base regions, an annular source region is diffused into each base, employing the same polysilicon window as an outer mask. A central oxide dot may be left in the center of each of the open windows so that the oxide is thicker at the central regions and remains in place during the diffusion of the source regions.
135 citations
Patent•
16 Nov 1989TL;DR: A power module contains IGBT die along with integrated circuit driver chips and opto isolators or isolation transformers within the same module housing as mentioned in this paper, which can be interfaced directly to control logic or microprocessors for operating the module.
Abstract: A power module contains IGBT die along with integrated circuit driver chips and opto isolators or isolation transformers within the same module housing. Output terminals are provided which can be interfaced directly to control logic or microprocessors for operating the module. The IGBTs may have current-sensing electrodes to simplify current measurement and control functions.
78 citations
Patent•
15 Jun 1989TL;DR: Two or more buck converter circuits are cascaded in such a manner that the output of one serves as the input to the next, with the input voltage to each succeeding buck converter stage being reduced in magnitude as mentioned in this paper.
Abstract: Two or more buck converter circuits are cascaded in such a manner that the output of one serves as the input to the next, with the input voltage to each succeeding buck converter stage being reduced in magnitude. The total circuit losses are substantially reduced as compared to the losses generated in a single buck converter having the same input voltage range and the same output voltage and output current. Both positive and negative output terminals may be provided for an output stage.
63 citations
Patent•
21 Sep 1989TL;DR: In this article, a silicon wafer containing preformed junctions is filled with a clean silicon surface and the wafer is heated to about 500° C. for a short time, which is high enough to cause the platinum atoms to diffuse into the silicon Wafer but is too low and lasts for too short a time to cause movement of the preformed joints within the Wafer.
Abstract: Platinum atoms are uniformly dispersed throughout a silicon wafer containing preformed junctions by depositing a layer of platinum on a clean silicon surface and thereafter immediately heating the wafer to about 500° C. to form platinum silicide. Alternatively, a layer of palladium may be deposited on the surface of the wafer, a layer of platinum is deposited atop the palladium and the wafer is heated to form a palladium silicide with platinum atoms uniformly dispersed throughout the silicide layer. The wafer is heated to about 900° C. for a short time which is sufficiently high to cause the platinum atoms to diffuse into the silicon wafer but is too low and lasts for too short a time to cause the movement of the preformed junctions within the wafer.
22 citations
Patent•
27 Oct 1989TL;DR: In this article, a universal battery charger circuit has polarized capacitors disposed in the input a-c lines to a bridge-connected rectifier, and voltage clamping circuit is connected to the d-c terminals of the bridge and diodes are connected in parallel with each of the polarized capacitor to define a circuit for the flow of charging current.
Abstract: A universal battery charger circuit has polarized capacitors disposed in the input a-c lines to a bridge-connected rectifier. A voltage clamping circuit is connected to the d-c terminals of the bridge and diodes are connected in parallel with each of the polarized capacitors to define a circuit for the flow of charging current. Regulation circuits are provided for both battery voltage and charging current so that any battery of given voltage output can be charged from different input voltage sources.
12 citations
01 Sep 1989
TL;DR: Electron irradiation has been used to modify the electrical characteristics and to enhance the switching speed of high power GTO thyristors and has been compared with that obtained in standard gold doped devices.
Abstract: Electron irradiation has been used to modify the electrical characteristics and to enhance the switching speed of high power GTO thyristors. The defects introduced by the impinging electrons have been annealed through several thermal steps, carried out at three different temperatures, after which the main electrical characteristics have been tested. The trade-off between static and dynamic characteristics, obtained with this method of lifetime control, has been compared with that obtained in standard gold doped devices. Special attention is paid to the control of power losses during the turn-off phase.