Offset calibration system and method for a high gain signal channel
AssigneeAnalog Devices, Inc.
InventorsAidan J. Cahalane, Simon Atkinson
Life of this patent
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Abstract
A direct current offset correction system is disclosed for use in an analog signal processing system. The offset correction system includes a comparator unit for comparing the polarity of signals from an analog signal channel and producing a binary output signal. The system also includes a digital accumulator unit that is coupled to the comparator output signal for providing an accumulated average signal over a predetermined period of time. The system also includes a threshold window digital comparator unit for determining whether the accumulated signal is within a defined threshold window of acceptable values. The system further includes a correction unit for applying a corrective signal to the analog signal channel.
Claims20
A direct current offset correction system for use in an analog signal processing system, said offset correction system comprising:
- comparator means for comparing polarity of signals from an analog signal channel and producing a binary output signal;
- digital accumulator means coupled to said comparator output signal for providing an accumulated average signal over a predetermined period of time;
- threshold window digital comparator means for determining whether said accumulated signal is within a defined threshold window of acceptable values;
- and
- correction means for applying a corrective current to said analog signal channel.
A direct current offset correction system for use in an analog signal processing system, said offset correction system comprising:
- comparator means for comparing polarity of signals from an analog signal channel and producing a comparator binary output signal;
- accumulator means coupled to said comparator output signal for providing an accumulated average signal over a predetermined period of time;
- reset means for resetting the accumulator means;
- and
- correction means for applying a corrective signal to said analog signal channel.
A direct current offset correction system for use in an analog signal processing system, said offset correction system comprising:
- comparator means for comparing polarity of signals from an analog signal channel and producing a comparator output signal responsive to a clock signal from a first clock;
- accumulator means coupled to said comparator output signal for providing an accumulated average signal over a predetermined period of time;
- threshold window comparator means coupled to a second clock signal that is relatively slow compared to said first clock signal, said window comparator means for determining whether said accumulated signal is within a defined threshold window of acceptable values;
- and correction means for applying a corrective signal to said analog signal channel.
A method of correcting for direct current offset in an analog signal processing system, said method comprising the steps of:
- a) receiving analog signals in an analog signal channel;
- b) comparing each of said analog signals with a reference to determine whether a direct current offset exists and producing a comparator output signal;
- c) accumulating a sum of comparator output signals over a predetermined period of time to determine an accumulated value;
- and
- d) applying a correction signal to the analog signal channel responsive to whether said accumulated value is outside of said window threshold.
Dependencies are inferred from the claim text.