DR. DAVID N YANG, O.D.
Optometry at Miranda Ave, Palo Alto, CA

6369737, Apr 9, 2002

Oct 30, 1997

08/960823

David Yang - Palo Alto CA
Abbas El Gamal - P. A. CA
Boyd Fowler - Sunnyvale CA

The Board of Trustees of the Leland Stanford Junior University - Palo Alto CA

H03M 112

341155, 341169

An analog-to-digital conversion scheme allows the conversion of a small dynamic range analog signal into a floating-point, digital representation with a larger dynamic range. A montonically changing analog signal is reset to a reference value at time t=0. The analog signal is then sub-converted by an analog-to-digital converter with maximum input signal level S to corresponding digital representations at several sub-conversion times t=T T t=T T ,. . . t=T T , where T T. These digital representations are then suitably combined to produce a cumulative, floating-point digital representation which accurately represents the analog signal even if the analog signal has a value greater than S at time t=T.

6538593, Mar 25, 2003

Feb 28, 2002

10/085341

David Yang - Palo Alto CA
Abbas El Gamal - P.A. CA
Boyd Fowler - Sunnyvale CA

The Board of Trustees of the Leland Stanford Junior University - Stanford CA

H03M 1102

341155, 341169

An analog-to-digital conversion scheme allows the conversion of a small dynamic range analog signal into a floating-point, digital representation with a larger dynamic range. A montonically changing analog signal is reset to a reference value at time t=0. The analog signal is then sub-converted by an analog-to-digital converter with maximum input signal level S to corresponding digital representations at several sub-conversion times t=T T , t=T T ,. . . t=T T , where T T. These digital representations are then suitably combined to produce a cumulative, floating-point digital representation which accurately represents the analog signal even if the analog signal has a value greater than S at time t=T.

5801657, Sep 1, 1998

Feb 5, 1997

8/795497

Boyd Fowler - Sunnyvale CA
David Yang - Stanford CA
Abbas El Gamal - Palo Alto CA

Stanford University - Palo Alto CA

H03M 138

341155

A method for simultaneously performing bit serial analog to digital conversion (ADC) for a potentially very large number of signals is described. The method is ideally suited for performing on chip ADC in area image sensors. In one embodiment, to achieve N-bit precision, the method employs a one-bit comparator per channel (or set of multiplexed channels) and an N-bit DAC. To achieve N bits of precision, 2. sup. N -1 comparisons are sequentially performed. Each comparison is performed by first setting the DAC output to the desired value and then simultaneously comparing each of the pixel values to that value. If a pixel value is greater than the DAC output value, its comparator outputs a one, otherwise it outputs a zero. By appropriately choosing the sequence of comparison values, the pixel values are sequentially generated. In another embodiment, the DAC is omitted and a continuous ramp signal is generated for comparison with the analog input.