A/D converter and D/A converter employing a rodix smaller than a two, and calibration thereof
AssigneeNokia Mobile Phones Ltd.
InventorPentti Mannonen
Life of this patent
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Abstract
A converter system is comprised of an analog-to-digital converter (1) and a digital-to-analog converter (2). A first base number of a number system used in the analog-to-digital converter is less than 2, and a second base number of a number system used in the digital-to-analog converter is less than two. The first base number does not equal the second base number. For example, both are within a range from 1.90 to 1.99. In a calibration method the output of the digital-to-analog converter is switched to the input of the analog-to-digital converter, and a controller (3) provides digital values to the input of the digital-to-analog converter, and receives corresponding digital values from the output of the analog-to-digital converter.
Claims14
A converter system comprising an analog-to-digital converter and a digital-to-analog converter, characterized in that a first base number of a number system used in the analog-to-digital converter is less than 2, further characterized in that a second base number of a number system used in the digital-to-analog converter is less than two, and wherein the first base number does not equal the second base number.
A method of calibrating an analog-to-digital converter, characterized in that the method comprises the steps of:
- providing a converter system having an analog-to-digital digital converter and a digital-to-analog converter, wherein a first base number of a number system used in the analog-to-digital converter is less than 2, wherein a second base number of a number system used in the digital-to-analog converter is less than two, and wherein the first base number does not equal the second base number;
- connecting an along input of the analog-to-digital converter alternately to a reference voltage corresponding to a zero value of a number range of the analog-to-digital converter and to a reference voltage corresponding to a largest value of the number range;
- storing conversion results output by the analog-to-digital converter;
- and
- calculating actual values or calibration values of weights of the analog-to-digital converter on the basis of the known reference voltage values and the stored conversion results corresponding to the known reference voltage values.
A method of calibrating an analog-to-digital converter, characterized in that the method comprises the steps of:
- providing a converter system having an analog-to-digital converter and a digital-to-analog converter, wherein a first base number of a number system used in the analog-to-digital converter is less than 2, wherein a second base number of a number system used in the digital-to-analog converter is less than two and wherein the first base number does not equal the second base number;
- connecting an analog input of the analog-to-digital converter to a voltage source supplying a voltage varying with time according to a known function covering an output number range of the analog-to-digital converter;
- connecting the analog input to a reference voltage corresponding to a zero value of the number range of the analog-to-digital converter;
- storing conversion results output by the analog-to-digital converter in response to both said known voltage source and said reference voltage;
- and
- calculating actual values or calibration values of weights of the analog-to-digital converter on the basis of said known voltage function, the reference voltage, and the stored conversion results corresponding to said known voltage function and the reference voltage.
A method of calibrating a converter system, characterized in that the method comprises the steps of:
- providing a converter system comprising an A/D converter and a D/A converter having analog sides connectable to each other for the calibration of at least the D/A converter, wherein the base numbers of the number systems used in the A/D converter and the D/A converter are mutually different and smaller than 2;
- connecting an analog input of the A/D converter alternately to a reference voltage corresponding to a zero value of a number range of the A/D converter, to a reference voltage corresponding to a largest value of the number range of the A/D converter, and to an analog output of the D/A converter;
- applying digital control values to the D/A converter when connected to the A/D converter;
- storing conversion results output from the A/D converter;
- and
- calculating actual values or calibration values of weights of the A/D and D/A converters when both converters are uncalibrated, or calculating the actual values or calibration vales of the weights of only the D/A converter when the A/D converter is calibrated in advance, on the basis of the known reference voltage values, the stored conversion results and the control values of the D/A converter.
A/D and D/A converter system comprising an A/D converter (1) and a D/A converter (2) having analog sides (12, 13) connectable to each other for the calibration of at least the D/A converter, characterized in that the base numbers of the number systems used in the converters (1, 2) are mutually different and smaller than 2.
Dependencies are inferred from the claim text.