Patents by Inventor Rahim Chowdhury

Rahim Chowdhury 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).

  • Capacitive touch sense architecture having a correlator for demodulating a measured capacitance from an excitation signal
    Patent number: 8878797
    Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: November 4, 2014
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Ozan E. Erdogan, Guozhong Shen, Rajesh Anantharaman, Ajay Taparia, Behrooz Javid, Syed T. Mahmud, Rahim Chowdhury
  • CAPACITIVE TOUCH SENSE ARCHITECTURE
    Publication number: 20130162586
    Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform.
    Type: Application
    Filed: February 23, 2012
    Publication date: June 27, 2013
    Applicant: MAXIM INTEGRATED PRODUCTS, INC.
    Inventors: Ozan E. Erdogan, Guozhong Shen, Rajesh Anantharaman, Ajay Taparia, Behrooz Javid, Syed T. Mahmud, Rahim Chowdhury
  • Replica compensated heterogeneous DACs and methods
    Patent number: 6642867
    Abstract: Digital to analog converters having a hybrid two-stage structure. The first stage is a differential segmented current DAC controlled by the MSBs (most significant bits) of input data. The second stage is a resistor string DAC controlled by the LSBs (least significant bits) of the input data to interpolate between the differential outputs of the first stage. The resistor string is directly connected to the current DAC without the need of buffer amplifiers. Instead, a replica circuit is used to prevent the second-stage resistor string from loading the first stage current DAC. Compensation techniques are described.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: November 4, 2003
    Assignee: Maxim Integrated Products, Inc.
    Inventors: Rahim Chowdhury, Bo Yang, David Castaneda