Patent ID: 11888492
Assignee: CIRRUS LOGIC INC.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A method of calibrating a system including an analog circuit and an analog signal comparator that compares outputs of an analog circuit, the method comprising:
alternatively operating the system in a first phase in which the analog circuit acquires an input signal and the analog signal comparator is being calibrated, and a second phase in which the outputs of the analog circuit are compared by the analog signal comparator, wherein a sampling cycle comprises operating the system in the first phase and then the second phase;
in the first phase, disconnecting the outputs of the analog circuit from inputs of a preamplifier stage of the analog signal comparator and applying a common mode reference to the inputs of the preamplifier stage of the analog signal comparator while sampling an output of the preamplifier stage of the analog signal comparator with a decision latch of the analog signal comparator;
determining an offset correction change dependent on a history of states of an output of the decision latch of the analog signal comparator across multiple sampling cycles of the system; and
applying the offset correction change to an offset input of the decision latch of the analog signal comparator to adjust a threshold voltage of the decision latch in conformity with the history of the states of the output of the decision latch.