Analog Devices,inc.

Baozhen Chen

Lalinda D Fernando

Mark D Maddox

Michael C W Coln

Edward Chapin Guthrie

Zhichao Tan

Michael C Coln

Gary Carreau

Micah Galletta O'Halloran

Frank M Yaul

Andrew Wayne Shaw

A self-routing capacitor for an integrated circuit having: a first electrode comprising a first base region and a first finger, the first finger extending from a wall of the first base region in a first direction; a second electrode comprising a second base region and a second finger; the second finger extending from a wall of the second base region in a second direction substantially parallel to and opposing the first direction, the second finger coupled to the first finger; a third electrode comprising a third base region and a third finger, the third finger extending from a first wall of the third base in the second direction; and a fourth electrode comprising a fourth finger, the fourth finger extending from a second wall of the third base region in the first direction. The capacitor being coupled to other metal layers through a base region of an electrode.

High density self-routing metal-oxide-metal capacitor

A method of performing analog-to-digital conversion using a successive approximation (SAR) analog-to-digital converter (ADC). A previous digital output is compared to a range based on the first M bits of the previous digital output. If the previous digital output is within that range, a digital-to-analog converter (DAC) of the SAR ADC is preloaded with the first M bits of the previous digital output, prior to commencing bit trials. If the previous digital output is outside of that range, an offset is applied to the first M bits of the previous digital output and the DAC is preloaded based on the M bits and the offset, prior to performing bit trials. This method reduces the possibility of the next input being outside of a further range defined by the preload.

Method of performing analog-to-digital conversion

During operation of a SAR ADC, several of the MSBs can be preloaded with predetermined bit decisions prior to carrying out bit trials. A system and method can be provided for incrementally preloading the predetermined bit decisions such as to maintain voltages present at comparator inputs within a limited range of acceptable input voltages.

Incremental preloading in an analog-to-digital converter

A self-adaptive SAR ADC techniques that can increase speed and/or decrease its power consumption. In some example approaches, one or more bits from a conversion of a previous sample of an analog input signal can be preloaded onto a DAC circuit of the ADC. If the preloaded bits are determined to be acceptable, bit trials on the current sample can be performed to determine the remaining bits. If not acceptable, the ADC can discard the preloaded bits and perform bit trials on all of the bits. The self-adaptive SAR ADC can include a control loop to adjust, e.g., increase or decrease, the number of bits that are preloaded in a subsequent bit trial using historical data.

Self-adaptive analog-to-digital converter

During operation of a SAR ADC, it is possible to exceed the voltage limits of a comparator by presenting voltages at the comparator input that exceed a limited range of acceptable input voltages. The present disclosure provides a system and method such as for delivering a common mode compensation voltage such that voltages present at the comparator inputs can be within the limited range of acceptable input voltages.

Systems and methods for generating a common mode compensation voltage in a SAR ADC

When reservoir capacitors are moved on-chip for individual bit decisions, a successive approximation register analog-to-digital converter (SAR ADC) has an addition source of error which can significantly affect the performance of the SAR ADC. Calibration techniques can be applied to measure and correct for such error in an SAR ADC using decide-and-set switching. Specifically, a calibration technique can expose the effective bit weight of each bit under test using a plurality of special input voltages and storing a calibration word for each bit under test to correct for the error. Such a calibration technique can lessen the need to store a calibration word for each possible output word to correct the additional source of error. Furthermore, another calibration technique can expose the effective bit weight of each bit under test without having to generate the plurality of special input voltages.

Calibration techniques for SAR ADCs with on-chip reservoir capacitors

In an example, a successive approximation register analog-to-digital converter includes a switched capacitor digital-to-analog converter (DAC) first array to sample an input signal and to convert a sample of the input signal to a digital value represented by a plurality of bits, the first array including a first group of capacitors representing at least some of the plurality of bits, a switched capacitor DAC second array including a second group of capacitors representing at least some of the plurality of bits, wherein at least one bit of the plurality of bits represented by the second group of capacitors is represented by at least two capacitors, and wherein each of the two capacitors is configured to be selectively connected to a selected one of at least two reference potentials such that the at least one bit represented by the second group of capacitors is switchable between at least three states.

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Woburn, MA, United States of America

Baozhen Chen