A/D converter system with error correction and calibration apparatus and method

An analog to digital converter system comprising:

• conversion circuitry operative for developing a digital output corresponding to the magnitude of an input analog signal, and error correction means associated with said conversion circuitry including means for developing digital data which defines predetermined transitory characteristics of said input analog signal, said error correction means being arranged to apply said characteristic-defining data to said address port for output from said data port of said digital correction signals which correspond to the applied characteristic-defining data, memory means including an address port and a data port for storing calibration data, and means for developing digital correction signals in accordance with a comparison of said calibration data and said characteristic-defining data, said conversion circuitry including logic means for receiving said digital correction signals in a direction to reduce error in said digital output therefrom and said conversion circuitry includes comparison means operative with respect to a certain sampling time for comparing the magnitude of said input analog signal with reference voltage levels, and wherein said characteristic-defining data include level-defining data determined by the highest of said reference voltage levels which is exceeded by said input analog signal.

An analog to digital converter system comprising:

• conversion circuitry operative for developing a digital output corresponding to the magnitude of an input analog signal, and error correction means associated with said conversion circuitry including means for developing digital data which defines predetermined transitory characteristics of said input analog signal, memory means for storing calibration data, and means for developing correction signals in accordance with a comparison of said calibration data and said characteristic-defining data, said conversion circuitry including means for receiving said digital correction signals in a direction to reduce error in said digital output therefrom, said conversion circuitry further including a first A/D converter for developing first digital data corresponding to the amplitude of said input analog signal at a certain sampling time, a second A/D converter for developing second digital data corresponding to the amplitude of said input analog signal at a second sampling time different from said certain sampling time, said characteristic-data including both said first digital data and said second digital data.

A method of analog to digital signal conversion, comprising the steps of:

• providing conversion circuitry having error correction circuits for including a memory having an address port which in normal operation is supplied with signals developed from an analog signal applied to an input port to develop an error correction signal to be effectively added at a digital output port in accordance with calibration data stored in the memory, providing a memory which is electrically alterable and a calibration port connected to address and data ports and a control line of the memory, testing the conversion circuitry to determine the relationship of the digital output to an applied analog signal and required error corrections and corresponding calibration data, then adjusting the conversion circuitry by applying digital data and a control signal through the calibration port to the address and data ports and control line of the electrically alterable memory to store the calibration data therein.

A method analog to digital conversion comprising the steps of sampling an analog input signal at first and second sampling times one delayed with respect to the other to develop first and second analog signals, converting the first and second analog signals to first and second digital signals, supplying calibration data, developing a digital error correction signal from said first and second digital signals and said calibration data, and developing an output digital signal from said first digital signal and said error correction signal.