Method and apparatus for start-up of analog-to-digital converters
First Claim
1. A method of calibrating an analog-to-digital converter circuit, comprising:
- disabling an input signal to the analog-to-digital converter circuit;
inputting a pseudo-random signal to the analog-to-digital converter circuit;
measuring at least one of estimated gain and estimated integrator pole of the analog-to-digital converter circuit; and
calculating coefficients of a calibration filter used in the analog-to-digital converter circuit using at least one of the estimated gain and the estimated integrator pole.
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Accused Products
Abstract
An analog-to-digital (ADC) converter circuit that converts an analog input signal into a digital output circuit includes a calibration coefficient computation circuit for computing calibration coefficients of a calibration filter. The calibration coefficient computation circuit includes a switching device adapted to switch the analog input signal delivered to the ADC circuit between on and off states, and includes a pseudo-random signal generator adapted to input a pseudo-random signal to the ADC circuit. During a start-up phase of the ADC circuit, the ADC circuit, the switching device turns off the analog input signal to the ADC circuit, the pseudo-random signal generator inputs a pseudo-random signal into the ADC circuit, and the calibration coefficient computation circuit computes the calibration coefficients of the calibration filter. This ADC circuit configuration reduces startup time for the calibration filter to only a few clock cycles.
89 Citations
37 Claims
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1. A method of calibrating an analog-to-digital converter circuit, comprising:
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disabling an input signal to the analog-to-digital converter circuit; inputting a pseudo-random signal to the analog-to-digital converter circuit; measuring at least one of estimated gain and estimated integrator pole of the analog-to-digital converter circuit; and calculating coefficients of a calibration filter used in the analog-to-digital converter circuit using at least one of the estimated gain and the estimated integrator pole. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of measuring calibration coefficients of a calibration filter used in a pipelined analog-to-digital converter circuit, the pipelined analog-to-digital converter circuit having a first analog-to-digital converter, a second analog-to-digital converter and a digital-to analog converter in a feedback path of the first analog-to-digital converter, the method comprising:
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disabling an input signal to the pipelined analog-to-digital converter circuit; inputting a pseudo-random signal to the pipelined analog-to-digital converter circuit; inputting a gained output of the digital-to-analog converter to the second analog-to-digital converter; and inputting the pseudo-random signal and the output of the second analog-to-digital converter to a calibration coefficient computation circuit to thereby calculate calibration coefficients. - View Dependent Claims (13, 14, 15)
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16. A method of measuring calibration coefficients of a calibration filter used in a Δ
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analog-to-digital converter circuit, the Δ
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analog-to-digital converter circuit having a first analog-to-digital converter, a second analog-to-digital converter and a digital-to analog converter in a feed-back path of the first analog-to-digital converter, the method comprising;disabling an input signal to the Δ
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analog-to-digital converter circuit;inputting a pseudo-random signal to the Δ
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analog-to-digital converter circuit;inputting an integrated output of the digital-to-analog converter to the second analog-to-digital converter; and inputting the pseudo-random signal and the output of the second analog-to-digital converter to a calibration coefficient computation circuit to thereby calculate calibration coefficients. - View Dependent Claims (17, 18, 19, 20)
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21. An analog-to-digital converter system for converting an analog input signal to a digital output signal, the circuit comprising:
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an analog-to-digital converter circuit; a switching device for turning on and turning off the analog input signal to the analog-to-digital converter circuit; a pseudo-random signal generator providing a pseudo-random signal to the analog-to-digital converter circuit, a calibration coefficient computation circuit to compute calibration coefficients of the analog-to-digital converter circuit; and a calibration filter circuit for filtering the digital output signal according to the calibration coefficients. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A calibration coefficient computation circuit for computing calibration coefficients of a calibration filter used in an analog-to-digital converter circuit, the analog-to-digital circuit converting an analog input signal into a digital output signal, the calibration coefficient computation circuit comprising:
a switching device adapted to turn on and turn off the analog input signal to the analog-to-digital converter and a pseudo-random signal generator adapted to input a pseudo-random signal to the analog-to-digital converter circuit, wherein the switching device turns of the analog input signal to the analog-to-digital converter circuit during a startup phase of the analog-to-digital converter circuit, the pseudo-random signal generator inputs a pseudo-random input signal into the analog-to-digital converter circuit during the startup phase and the calibration coefficient computation circuit computes the calibration coefficients of the calibration filter during the startup phase. - View Dependent Claims (32, 33, 34, 35, 36, 37)
Specification