Patents by Inventor T. Lakshmi Viswanathan

T. Lakshmi Viswanathan 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: 7277519
    Abstract: In one embodiment, a system for frequency and phase correction in a phase-locked loop (PLL) includes a phase frequency detector, first and second charge pumps respectively generating a first current and a voltage, a voltage-to-current (V2I) converter, a current summer, and a current-controlled oscillator (CCO). The phase frequency detector detects a frequency difference and a phase difference between a clock signal and a comparison signal, communicates the frequency difference to a first charge pump generating a first current, and communicates the phase difference to a second charge pump generating a voltage. The comparison signal is derived from an output signal of the PLL. The first charge pump modifies the first current according to the frequency difference and communicates the first current to the current summer. The second charge pump modifies the voltage according to the phase difference and communicates the voltage to the V2I converter.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: October 2, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Prasun K. Raha, T. Lakshmi Viswanathan, Richard E. Jennings
  • Patent number: 6940337
    Abstract: An apparatus includes a voltage regulator operable to regulate a supply voltage to an on-chip module having an operational current, draw a supply current, and supply the operation current to the on-chip module. The supply current drawn by the voltage regulator is proportional to the operating current of the on-chip module.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: September 6, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: T. Lakshmi Viswanathan, Prasun K. Raha
  • Patent number: 6501411
    Abstract: A pipelined data converter current biasing system employs a frequency-to-voltage converter (FVC) operational to convert a plurality of desired sampling frequencies to a plurality of output voltages and a voltage-to-current (V to I) converter operational to convert the plurality of output voltages to a plurality of bias currents. The plurality of bias currents function to bias the data converter operational amplifiers such that the data converter power consumption is dependent on the plurality of sampling frequencies in a way that optimizes power consumed by the data converter with respect to the sampling frequency.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: December 31, 2002
    Assignee: Texas Instruments Incorporated
    Inventors: Karthikeyan Soundarapandian, Eric G. Soenen, T. Lakshmi Viswanathan
  • Patent number: 6018269
    Abstract: A method for producing gain in an electrical signal includes providing a variable resistance system having a plurality of transistors connected in parallel and controlling the resistance of the variable resistance system by applying a voltage to a control node of each of the plurality of transistors to selectively turn each transistor on or off. The method also includes receiving a differential input voltage and applying the differential input voltage across the variable resistance system to produce a signal current. The method also includes providing at least a portion of the signal current to a load resistance system to generate a differential output voltage and setting the ratio of the differential output voltage to the differential input voltage by controlling the voltage applied to the control node of each of the plurality of transistors.
    Type: Grant
    Filed: December 23, 1997
    Date of Patent: January 25, 2000
    Assignee: Texas Instruments Incorporated
    Inventor: T. Lakshmi Viswanathan