Analog to digital conversion for a CMOS imager
First Claim
1. An analog-to-digital (A/D) converter, comprising:
- an input, for receiving a series of analog signals;
an output, for outputting a series of digital signals respectively corresponding to said series of analog signals;
a plurality of A/D cells, each of said A/D cells for converting one of said series of analog signals to a corresponding one of said series of digital signals; and
a control circuit, coupled to said input, said output, and said plurality of A/D cells;
wherein said control circuit operates said input, said output, and said plurality of A/D cells so that each successive A/D cell is assigned, at a different time, to convert a different one of each successive analog signal from said series of analog signals to a corresponding digital signal in said series of digital signals.
1 Assignment
0 Petitions
Accused Products
Abstract
An image sensor system using offset analog to digital converters. The analog to digital converters require a plurality of clock cycles to carry out the actual conversion. These conversions are offset in time from one another, so that at each clock cycle, new data is available.A CMOS image sensor converts successive analog signals, representing at least a portion of an image, into successive digital signals using an analog to digital circuit block. Multiple clock cycles may be used by the circuit block to fully convert an analog signal into a corresponding digital signal. The conversion of one analog signal into a corresponding digital signal by the circuit block may be offset in time and partially overlapping with the conversion of a successive analog signal into its corresponding successive digital signal by the circuit block.
24 Citations
28 Claims
-
1. An analog-to-digital (A/D) converter, comprising:
-
an input, for receiving a series of analog signals; an output, for outputting a series of digital signals respectively corresponding to said series of analog signals; a plurality of A/D cells, each of said A/D cells for converting one of said series of analog signals to a corresponding one of said series of digital signals; and a control circuit, coupled to said input, said output, and said plurality of A/D cells; wherein said control circuit operates said input, said output, and said plurality of A/D cells so that each successive A/D cell is assigned, at a different time, to convert a different one of each successive analog signal from said series of analog signals to a corresponding digital signal in said series of digital signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for converting a series of analog signals to a corresponding series of digital signals, comprising:
-
receiving over a period of time, a series of analog signals; assigning each analog signal from said series of analog signals as they are received to an available A/D cell for analog-to-digital conversion to a corresponding digital signal; and outputting a different digital signal corresponding to a respective analog signal from said series of analog signals as each A/D cell finishes its analog-to-digital conversion; wherein at least two A/D cells are performing respective analog-to-digital conversions while another A/D cell outputs one of said digital signals. - View Dependent Claims (11, 12, 13, 14)
-
-
15. A method comprising:
-
receiving light on an array of photoreceptors of a CMOS imager, the light forming at least a portion of an image; converting the light into successive analog signals; providing the successive analog signals to an input of an analog to digital (A/D) converter of the CMOS imager during a first period of time; and determining at least one bit of respective successive digital signals corresponding to the successive analog signals, respectively, during a second period of time that begins after the first period of time ends. - View Dependent Claims (16, 17, 18, 19, 20)
-
-
21. A method comprising:
-
converting an image impinging upon a CMOS imager array into analog signals; providing a first analog signal associated with the image to an input of an analog to digital (A/D) converter of the CMOS imager, and, during a first time period, the A/D converter converting the first analog signal into a corresponding first digital signal; providing a second analog signal associated with the image to the input of the A/D converter, and, during a second time period, the A/D converter converting the second analog signal into a corresponding second digital signal; and providing a third analog signal associated with the image to the input of the A/D converter, and, during a third time period, the A/D converter converting the third analog signal into a corresponding third digital signal, wherein the first, second, and third time periods are offset from each other and partially overlapping. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
-
Specification