Patents by Inventor Sergio R. Ramirez

Sergio R. Ramirez has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7986195
    Abstract: Provided are apparatuses and methods for digital FM modulation. In one example, a message signal is integrated by an integrator to transform the message signal into a complex signal. The complex signal may include at least two complex components that may interfere to produce an FM modulated carrier signal. Hence, in this example, the method and apparatus for digital FM modulation may produce an FM modulated carrier signal without phase shifting. In another example, a lookup table is not necessary for modulation of the carrier signal.
    Type: Grant
    Filed: February 25, 2008
    Date of Patent: July 26, 2011
    Assignee: Mentor Graphics Corporation
    Inventor: Sergio R. Ramirez
  • Publication number: 20080204159
    Abstract: Provided are apparatuses and methods for digital FM modulation. In one example, a message signal is integrated by an integrator to transform the message signal into a complex signal. The complex signal may include at least two complex components that may interfere to produce an FM modulated carrier signal. Hence, in this example, the method and apparatus for digital FM modulation may produce an FM modulated carrier signal without phase shifting. In another example, a lookup table is not necessary for modulation of the carrier signal.
    Type: Application
    Filed: February 25, 2008
    Publication date: August 28, 2008
    Applicant: MENTOR GRAPHICS CORPORATION
    Inventor: Sergio R. Ramirez
  • Patent number: 6255747
    Abstract: A protection device for vertically standing lamps devices is described. The protection device consists of a switch or other means of interrupting the electrical current in case of a fall. The preferred embodiment of the invention is a normally open switch installed at the base of the lamp. This switch is closed by the action of lamp's own weight.
    Type: Grant
    Filed: September 4, 1999
    Date of Patent: July 3, 2001
    Inventors: Sergio R. Ramirez, Emanuel Shah
  • Patent number: 5982815
    Abstract: An apparatus for setting a device into a test mode. The apparatus has a first input port for receiving a fixed, constant signal during a normal mode of the device, and for receiving a non-fixed, clocked signal so as to set the device into a test mode. The apparatus also has a second input port for receiving a non-fixed, clocked signal during the normal mode and for receiving a fixed, constant signal so as to set the device into the test mode. When both the first input port receives the non-fixed, clocked signal and the second input port receives the fixed, constant signal for a predetermined amount of time, the device is placed into the test mode.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: November 9, 1999
    Assignee: Advanced Micro Devices Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5781053
    Abstract: A positive edge triggered flip flop which includes a master stage and a slave stage. The master stage includes an inverter that receives a clock input (C), and a first NAND gate having one input port for receiving a data input (D). The master stage also includes a second NAND gate and a first NOR gate that have their respective output connected to an input port of the other gate. The slave stage receives an inverted clock output from the inverter of the master stage. The slave stage includes a third NAND gate and a second NOR gate that also have their respective output connected to an input port of the other gate. An output value (Y) is read from the output of the second NOR gate.
    Type: Grant
    Filed: August 21, 1996
    Date of Patent: July 14, 1998
    Assignee: Advanced Micro Devices Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5760612
    Abstract: An inertial delay circuit includes a negative glitch removing circuit connected in series with a positive glitch removing circuit. The negative and positive glitch removing circuits are respectively configured to pass only negative and positive pulses of an input signal having a pulse width greater than a pre-determined width. The negative glitch removing circuit passes its input through a delay line and performs a logical OR on its input and the delayed signal. The positive glitch removing circuit passes its input through a delay line and performs a logical AND on its input and the delayed signal. The glitch removing circuits may further include respective pulse width restoring circuits to restore the pulses passing therethrough to their original widths.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: June 2, 1998
    Assignee: Advanced Micro Devices Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5731760
    Abstract: A fuse protection and fuse blowing circuit includes a fuse register which has an additional fuse with respect to other fuse registers used in the system. The additional fuse has an output which indicates a blown/not blown state of the additional fuse, and that output is fed back to a blow enable input of each of the other fuses in the fuse register and the other fuse registers. When the additional fuse is set to the blown state, none of the other fuses are allowed to be blown, thereby protecting the device against any accidental blowing of fuses.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: March 24, 1998
    Assignee: Advanced Micro Devices Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5638440
    Abstract: A power-cross detection circuit includes a zero crossing detection circuit for detecting a first zero crossing of the current from a first positive half-cycle to a first negative half-cycle, a second zero crossing of the current from a second positive half-cycle to a second negative half-cycle, and a third zero crossing of the current from a third positive half-cycle to a third negative half-cycle and a circuit for detecting a voltage level and outputting a first signal when the voltage level exceeds a predetermined voltage level, between the first zero crossing and the second zero crossing and between the second zero crossing and the third zero crossing. The zero crossing detection circuit outputs a second signal based on the first, second and third zero crossings.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 10, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Michael A. Nix, Walter S. Schopfer, Sergio R. Ramirez
  • Patent number: 5636273
    Abstract: An apparatus for determining a power cross condition during a ringing state of a telephone. The apparatus also is capable of distinguishing a true power cross condition from a short loop ringing condition, by including a first path for receiving a signal indicative of a voltage across a ring feed resistor exceeding a predetermined value, and determining if that voltage is in an active state for a predetermined amount of time (i.e., 14 milliseconds). The apparatus also includes a second path for receiving a first and second current that flow respectively across a first and second sense resistor connected to opposite ends of the ring feed resistor. On the second path, the first and second currents are subtracted, converted to a digital value, filtered, and compared to a threshold value to determine if a ring trip has occurred. If so, the potential ring trip is sent to a persistence timer circuit, for checking if it is in an active state for a predetermined amount of time (i.e., 104 milliseconds).
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 3, 1997
    Inventors: Walter S. Schopfer, Sergio R. Ramirez
  • Patent number: 5627536
    Abstract: A multiplexed delta-sigma modulator for performing analog to digital conversion on a plurality of input analog signals. These input analog signals are input to a multiplexer, where the input analog signals are converted into a single, time-division multiplexed analog signal. The time-division multiplexed analog signal is then received by the delta-sigma modulator, which oversamples the input signal and outputs a time-division multiplexed digital signal. The time-division multiplexed digital signal is then sent to a decimator which outputs a time-division multiplexed digital signal at a rate corresponding to the Nyquist rate of the input analog signals.The signal is sent from the decimator to a first down-sampler, and then to a demultiplexer, where the time-division multiplexed, decimated signal is sent to the appropriate output port of the demultiplexer at a sequential rate corresponding to the sequential rate utilized by the input multiplexer.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: May 6, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5514987
    Abstract: A regenerative comparator provides the capability of operating faster than a traditional regenerative comparator and the hysteresis points can be individually set and fine tuned. The regenerative comparator includes a current mirror having an input transistor connected to first and second output transistors, a first and second reference current sources which are set at a first and second predetermined level, respectively. An outputs of the first and second output transistors are provided to the latch through an inverter. The output of the latch transitions from a first logical output state to a second logical output state when an input current increases from a magnitude less than the first predetermined level to a magnitude greater than the first predetermined level.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: May 7, 1996
    Assignee: Advanced Micro Devices Inc.
    Inventor: Sergio R. Ramirez
  • Patent number: 5495513
    Abstract: A counter cell includes a latch circuit, control circuit, and a pull-up circuit. The latch circuit is formed of a first clocked half-latch, a second clocked half-latch and an inverter for storing a binary output signal. The first clocked half-latch is responsive to a first clock phase signal for transferring the binary output signal from its input to its output. The second clocked half-latch is responsive to a second clock phase signal for transferring a binary output signal from its input to its output. The control circuit is responsive to an input complement signal for selectively passing the first clock phase signal to the first clocked half-latch so as to permit toggling the state of the binary output signal. The control circuit requires only one transistor and two input signals to perform its required functions. When the input complement signal is High and the first phase input clock signal is High, an enable signal is sent to the first clocked half-latch, thereby enabling the count process.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: February 27, 1996
    Assignee: Advanced Micro Devices Inc.
    Inventors: Sergio R. Ramirez, Imran Baoai