Patents Assigned to Signetics
  • Patent number: 5015604
    Abstract: The size of a fusible link (22C.sub.F) created from part of a metal layer (22) is controlled by an oxidation performed in a deposition chamber that is also used for depositing a dielectric layer (30) over the fuse structure. The metal layer serves as a diffusion barrier between semiconductor material (14 and 16) and another metal layer (24).
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: May 14, 1991
    Assignee: North American Philips Corp., Signetics Division
    Inventors: Sheldon C. P. Lim, Julie W. Hellstrom, Ting P. Yen
  • Patent number: 5006476
    Abstract: In a transistor fabrication process, the use of a three-step base doping technique enables the characteristics of a vertical bipolar transistor to be controllably reproduced at highly optimal values from run to run. Insulating spacers (52A) are employed in forming a self-aligned base contact zone (58B). A shallow emitter (46) is created by outdiffusion from a patterned non-monocrystalline semiconductor layer (38A) that serves as the emitter contact. The fabrication process is compatible with the largely simultaneous manufacture of an insulated-gate field-effect transistor of the lightly doped drain type.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: April 9, 1991
    Assignee: North American Philips Corp., Signetics Division
    Inventors: Jan L. De Jong, Jacob G. DeGroot
  • Patent number: 4976809
    Abstract: Aluminum alloy polycrystalline conductors having reduced electro-migration tendencies are formed in a semiconductor device by applying a thin film of aluminum or aluminum alloy to an array of shallow holes provided in a dielectric layer the array being patterned according to a desired interconnection pattern. A thin film of aluminum or aluminum alloy is then scanned with a laser beam sufficient to melt the film and cause it to planarize. An oriented crystal structure is formed with grain boundaries being aligned orthogonally to the rows and column of the hole pattern. A photoresist mask is then aligned with the resultant crystal structure in a manner such that boundaries extend substantially only in a direction across the width of the desired conductor lines. The aluminum which is present in the crystal structure outside the desired conductor line is then removed by plasma etching through the mask.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: December 11, 1990
    Assignee: North American Philips Corp, Signetics Division
    Inventor: Eliot K. Broadbent
  • Patent number: 4963772
    Abstract: A D-type flip-flop arrangement includes first and second latches .Circuitry interposed between the latches blocks any metastable condition that may occur in the first latch from propagating into the second latch. Additionally, the arrangement minimizes the likelihood that the first latch will enter a metastable condition and, if it does, resolves the condition extremely rapidly.
    Type: Grant
    Filed: February 7, 1989
    Date of Patent: October 16, 1990
    Assignee: North American Philips Corp., Signetics Div.
    Inventor: Charles E. Dike
  • Patent number: 4946803
    Abstract: A Schottky-type diode is fabricated by a process that enables the diodes conductor-to-semiconductor barrier height .phi..sub.B to be controlled by adjusting the thickness of a metal silicide layer (22) which forms a rectifying junction (20) with an N-type semiconductor (24). In fabricating one version of the diode, a metallic layer (70) consisting of two or more metals such as platinum and nickel is deposited on an N-type silicon semiconductor (68) and heated to create a metal silicide layer (72) consisting of a lower layer (62) and an upper layer (74) of different average composition. A portion of the upper layer is then removed, allowing .phi..sub.B to be adjusted suitably.
    Type: Grant
    Filed: December 8, 1988
    Date of Patent: August 7, 1990
    Assignee: North American Philips Corp., Signetics Division
    Inventor: Russell C. Ellwanger
  • Patent number: 4939517
    Abstract: An electronic circuit contains a main stage (10 and 12) that produces a digital code consisting of a plurality of bits (B.sub.1 -B.sub.M-1) that make binary transitions as a function of an input parameter (V.sub.I). A synchronization stage (14 and 16) synchronizes transitions of bits (B.sub.0 -B.sub.K-1) in one part of the code with corresponding transitions of bits (B.sub.K -B.sub.M-1) in another part. When the input parameter is in transition regions where bits in the first-mentioned part of the code could go to wrong values, the synchronization stage suitably replaces the values of bits in the first part with information based on bits in the other part.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: July 3, 1990
    Assignee: North American Philips Corporation, Signetics Division
    Inventors: Peter G. Baltus, Rudy J. van de Plassche
  • Patent number: 4937657
    Abstract: A self-aligned metallization for an MOS device is described in which a first layer of tungsten is selectively deposited on the exposed silicon surfaces of the device including at least the source, drain and gate regions of the device, a layer of material providing nucleation sites for tungsten is selectively formed across insulating oxide regions of the device, and a second tungsten layer is selectively deposited on the nucleating layer and the exposed first tungsten layer to provide interconnection across the oxide regions. In addition to having a low electrical resistivity, such a metallization enables relaxed mask alignment and etching tolerance requirements, and is therefore useful in VLSI circuits.
    Type: Grant
    Filed: December 8, 1988
    Date of Patent: June 26, 1990
    Assignee: Signetics Corporation
    Inventors: Janet M. DeBlasi, Paulus Z. A. Van Der Putte
  • Patent number: 4933736
    Abstract: A semiconductor PROM contains a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22) fully adjoining a recessed oxide insulating region (16). A composite buried layer consisting of buried regions (32) which adjoin the insulating region below the lower cell regions (20) and an opposite-conductivity buried web (44) which laterally surrounds each buried region is employed to improve programming efficiency. Connective regions (46) extend from the buried web to the upper semiconductor surface to contact electrical leads (54) typically arranged in a parallel pattern. The maximum dopant concentration in the intermediate cell regions occurs vertically within 20% of their mid-points.
    Type: Grant
    Filed: March 10, 1989
    Date of Patent: June 12, 1990
    Assignee: North American Philips Corporation, Signetics Division
    Inventors: George W. Conner, Raymond G. Donald, Ronald L. Cline
  • Patent number: 4918398
    Abstract: A differential amplifier coupled between sources of a high supply voltage (V.sub.HH) and a low supply voltage (V.sub.LL) contains a pair of differential portions (30 and 32) that are used to amplify a differential input signal (V.sub.11 and V.sub.12). One of the differential portions is turned on when the common-mode voltage of the input signal is in a portion of the supply range extending up to the high supply voltage. The other is turned on when the input common-mode voltage is in a portion of the supply range extending down to the low supply voltage. A level-shift circuit (38, 40, 42, 44, and 46) selectively raises or loweres the voltages at input points (P1, P2, P3, and P4) to the differential portions. The level shifts extend the conductive ranges of the differential portions. This enables the amplifier to achieve rail-to-rail input capability down to 1 volt or slightly less for the power supply voltage.
    Type: Grant
    Filed: February 10, 1989
    Date of Patent: April 17, 1990
    Assignee: North American Philips Corporation, Signetics Division
    Inventors: Johan H. Huijsing, Marien G. Maris
  • Patent number: 4905137
    Abstract: Page-mode-organized ROMs and associated circuitry are connected only to data and control buses in an information processing system. Addressing and reading of the ROMs are controlled by a processor without connecting the ROMs to an address bus. Selection of a particular ROM and of a particular page in the selected ROM is accomplished by applying a first control signal to the control bus and a first data word to the data bus. This first data word thus serves as the address of the selected page in the selected ROM. Then a particular byte of the selected page is selected by applying a second control signal to the control bus and a second data word to the data bus. This second data word serves as the address of the selected byte. Subsequently, in response to a third control signal, the selected byte is read out of the selected ROM and applied to the data bus.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: February 27, 1990
    Assignee: North American Philips Corporation Signetics Division
    Inventors: Gregory K. Goodhue, William J. Price, Ronald L. Treadway, Brian M. Willis
  • Patent number: 4897656
    Abstract: The invention centers around a system for interpolating between multiple pairs of complementary main signals to generate further pairs of complementary signals. An input circuit (10) supplies the main signals. The interpolation is a two-step operation. The first step is done with two strings (S and S.sub.N) of impedance elements (R.sub.0 -R.sub.N-1 and R.sub.N0 -R.sub.NN-1). Each pair of main signals is supplied to a corresponding pair of nodes along the strings. Interpolated signals are taken from other pairs of corresponding nodes along the strings. In the second interpolation stage, a delay network (D) formed with additional impedance elements (R.sub.D0 -R.sub.DN-1 and R.sub.DN0 -R.sub.DNN-1) compensates for transmission delays through the impedance elements that make up the strings.
    Type: Grant
    Filed: December 2, 1987
    Date of Patent: January 30, 1990
    Assignee: North American Philips Corporation, Signetics Division
    Inventors: Rudy J. van de Plassche, Peter G. Baltus
  • Patent number: 4896333
    Abstract: A transceiver device has a transmitter circuit for transmitting data from a local data terminal to a computer network. The transmitter circuit has a voltage-to-current converter including a voltage divider with a plurality of voltage threshold taps, each voltage tap having a fixed voltage level; and a plurality of differential current switches each having first and second differential inputs, and a current differential output. Each of the first differential inputs is connected in common for receiving a voltage signal, and the second differential inputs are connected to an associated one of the voltage threshold taps. The current switch outputs are directly connected to a common node, to provide a current signal stepwise the same as the voltage signal. Preferably the common node is connected to a current amplifier including a simple filter. The output current waveform is preferably a trapezoidal waveform having matched rise and fall times.
    Type: Grant
    Filed: August 4, 1987
    Date of Patent: January 23, 1990
    Assignee: Signetics Corporation
    Inventor: Sumer Can
  • Patent number: 4878181
    Abstract: A circuit which expands monochrome character image patterns to color form for use in a raster scanned computer display system. Monochrome patterns are expanded from one bit per pixel to n bits per pixel. Foreground and background colors are programmable in a pattern generator which uses data from the expanded source patterns to select appropriate colors and characters for a destination pattern to be displayed. The expanded multicolor image is generated by hardware.
    Type: Grant
    Filed: November 13, 1987
    Date of Patent: October 31, 1989
    Assignee: Signetics Corporation
    Inventors: Craig A. MacKenna, Jan-Kwei J. Li
  • Patent number: 4874971
    Abstract: An edge-sensitive dynamic switch center around a transmission gate (16) formed with a pair of complementary FET's (Q.sub.N and Q.sub.P) coupled together in parallel between a pair of nodes (1 and 2). The signals at the two nodes vary between a low voltage level and a high voltage level. An inverter (17) is coupled between the gate electrodes of the FET's. A delay element (18) is coupled between one of the nodes and one of the gate electrodes. Due to the transmission delays through the delay element and the inverter, the switch turns off with a controlled delay.
    Type: Grant
    Filed: April 8, 1988
    Date of Patent: October 17, 1989
    Assignee: North American Philips Corporation, Signetics Division
    Inventor: Thomas D. Fletcher
  • Patent number: 4870417
    Abstract: An error correction circuit employs a digital averaging technique to overcome transition bit errors in a plurality of original binary bits ideally arranged as a thermometer or circular code. The circuit first generates a like plurality of intermediate signals respectively corresponding to the original bits. Each intermediate signal varies according to a weighted analog summation of a specified odd number of consecutive original bits centered about the corresponding bit. The circuit then compares the intermediate signals with corresponding further signals to produce a corrected code.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: September 26, 1989
    Assignee: North American Philips Corporation, Signetics Division
    Inventors: Rudy J. van de Plassche, Peter G. Baltus
  • Patent number: 4868628
    Abstract: A CMOS, N-well, P-channel static RAM cell with merged bipolar transistors as its output drivers.
    Type: Grant
    Filed: August 22, 1984
    Date of Patent: September 19, 1989
    Assignee: Signetics Corporation
    Inventor: George H. Simmons
  • Patent number: 4855622
    Abstract: A TTL compatible buffer circuit responsive to an input signal and having a controlled ramp output is disclosed and includes a low and a high output voltage driver, each driver being comprised of a Darlington pair of transistors, and each driver being separately controlled by its own control circuit. Each control circuit includes at least a capacitor and resistor which are arranged to control the voltage at the base of the upper transistor of the Darlington pair output voltage driver. In this manner, the voltage at the high voltage driver increases in a substantially linear manner when the input signal goes from low to high, and the voltage at the low voltage driver decreases in a substantially linear manner when the input signal goes from high to low. The turn on time of the drivers is thus relatively long. Each control circuit further includes a transistor which permits the respective output voltage driver to turn off quickly.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: August 8, 1989
    Assignee: North American Philips Corporation, Signetics Division
    Inventor: Derrell Q. Johnson
  • Patent number: 4851759
    Abstract: A highly accurate current-limiting circuit prevents an output current (I.sub.OUT) flowing through an output line (L.sub.OUT) from exceeding a specified value (I.sub.LIM) of an input current (I.sub.IN) flowing through an input line (L.sub.IN). The circuit contains a first channel device (10) controlled by a first reference voltage (V.sub.REF1), a current source (12) that supplies a reference current (I.sub.REF), a second channel device (14) controlled by a second reference voltage (V.sub.REF2), a current bypass device (16), and a bypass control system (18). The current gain below the specified value of the input current is close to one. By suitably choosing certain of the circuit parameters, the circuit operates in a substantially temperature-independent manner.
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: July 25, 1989
    Assignee: North American Philips Corporation, Signetics Division
    Inventor: Robert A. Blauschild
  • Patent number: 4849659
    Abstract: An ECL circuit (30.sub.1) formed with a pair of emmitter-coupled bipolar transistors (Q1.sub.A and Q1.sub.B), a main current source (26), a resistor (R1.sub.A), and an output transistor (Q2) contains a switching stage (38) for placing the circuit in the three-state mode when the circuit is operated in the normal ECL output voltage range. The switching stage causes current exceeding that supplied by the current source to flow through the resistor. The output transistor turns off, enabling the circuit to exhibit high output impedance.
    Type: Grant
    Filed: December 15, 1987
    Date of Patent: July 18, 1989
    Assignee: North American Philips Corporation, Signetics Division
    Inventor: Jeffery A. West
  • Patent number: 4845466
    Abstract: A transceiver system for high speed, low bit-error rate data communications over a.c. power lines in the presence of repetitive impulse noise includes an a.c. power line coupling network, a power line communications modem, and a microprocessor with a memory and a programmed avoidance algorithm. The a.c. line coupling network includes a zero crossing circuit to detect the start of each a.c. cycle; a transient-voltage limiting front end to detect impluse noises above a threshold and minimize ringing, and a timing circuit to determine the time and duration of each impulse in each sampled a.c. cycle. The microprocessor records the start and stop times of impulses, repetitively scans several a.c. cycles and determines whether or not the impulses are periodic. For periodic impulses, the microprocessor blocks communication on the modem during the impulses, enabling the transceiver to transmit and receive between impulses.
    Type: Grant
    Filed: August 17, 1987
    Date of Patent: July 4, 1989
    Assignee: Signetics Corporation
    Inventors: Dan I. Hariton, Prasanna M. Shah