A to D converter data calibration in real-time delivers faster conversion rates

The new digital data calibration technique allows any pipeline ADC to operate at a speed about 2 bits faster than currently available ADCs. For example, an 8-bit ADC could potentially run at 12 bits, compared to only the 10 bits maximum that might be possibly be achieved today.

The increase in speed is a result of when the data calibration is done. Existing ADCs calibrate data twice: initially when the chip is manufactured; and then continually as a background process during data conversion. However, the background calibration takes time and it must interrupt ADC operations. As a result, the full bit potential of an ADC cannot be achieved or maintained. The new calibration technique allows for both the initial and continual calibrations to be done in real time; that is, as the data is converted. By operating in real time, the maximum bit resolution of up to 12 bits can be achieved.


Analog to digital converters (ADCs) are most well known for their use in audio and visual products: they convert analog sound and motion data into digital data that can be stored in files. Digital cameras, cellular telephones, wireless data network equipment, audio devices (MP3 players), video devices (DVD players) and high definition television all use ADCs. Less well known, but equally important in their fields, ADCs are used to convert any type of continuous signal into digital data, including measuring voltage and currents, and recording ultrasonic medical images.

During conversion, errors can be introduced into the digital data. To minimize errors, the digital data must be continuously calibrated and corrected. Drs. Ham and Sun developed a new calibration technique for ADCs that operate at medium frequencies; also referred to as pipeline ADCs. Audio and video equipment typically use pipeline ADCs. The new calibration technique allows the ADC to generate digital data faster and more accurately than currently available ADCs can. This calibration technique could be used by any ADC maker to improve the performance and reliability of their pipeline converters.

U.S. Patent(s) Issued: US8031092B1