Capacitively-coupled continuous-time input pipeline adc with dynamic refresh and cmrr digital enhancement
AssigneeAvago Technologies International Sales Pte. Limited
InventorsKareem Abdelghani Ibraheem Mohamed Ragab, Vinay Chandrasekhar, Xicheng Jiang
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Abstract
An apparatus for analog-to-digital conversion comprising a first module with a comparator and digital-to-analog converters, and a second module with an amplifier. The apparatus implements input chopping by connecting capacitors to differential inputs through switches, and output chopping via an output chopper. Dynamic refresh is achieved using a switch to periodically connect differential inputs to a voltage reference. The apparatus further incorporates digital common-mode rejection ratio (CMRR) enhancement by processing signals from pseudo-differential first stage analog-to-digital converters.
Claims20
An apparatus comprising:
- a first module comprising a comparator, a first digital-to-analog converter and a second digital-to-analog converter;
- and
- a second module comprising an amplifier,
- wherein an output from the first digital-to-analog converter is wired directly to a first differential input of the comparator and a first differential input of the amplifier, and
- wherein an output from the second digital-to-analog converter is wired directly to a second differential input of the comparator and a second differential input of the amplifier.
A system comprising:
- a controller configured to repetitively alternate the system between a refresh mode and a chopping mode;
- and
- a first module comprising a switch and a comparator,
- wherein the switch is configured to:
- electrically connect, to a voltage while the system is in the refresh mode, a first differential input of the comparator and a second differential input of the comparator, and
- disconnect, from the voltage while the system is in the chopping mode, the first differential input of the comparator and the second differential input of the comparator.
A method comprising:
- alternating, repetitively by a controller, an apparatus between a refresh mode and a chopping mode;
- electrically connecting, by a switch while the apparatus is in the refresh mode, a first differential input of a comparator and a second differential input of the comparator to a voltage;
- and
- disconnecting, by the switch while the apparatus is in the chopping mode, the first differential input of the comparator and the second differential input of the comparator from the voltage.
Dependencies are inferred from the claim text.