Texas Instruments Corporation

Analog Devices,inc.

Ramesh Kumar Singh

Visvesvaraya Appala Pentakota

Nitin Kumar Agarwal

Abhaya Kumar

Eamonn J Byrne

Srikanth Aruna Nittala

Supreet Joshi

Dantes John

Chun Chieh Lee

Asif Ahmad

Visvesvarya Pentakota A

Shubha Govindachar

An offset correction circuit examines a residue signal of a stage of a pipeline analog to digital converter (ADC) to determine whether a parameter which could cause offset error, needs to be adjusted. In an embodiment, the parameter is adjusted until a maximum range of the residue signal equals an expected range. In the described examples, the adjusted parameters include timing offset error (when components of an ADC sample the input signal at different time instances) and a voltage offset error (the threshold voltage at which a sub-ADC in a stage the generated sub-code changes to a next value).

Correcting offset errors associated with a sub-ADC in pipeline analog to digital converters

A comparator presents a linear load to input signals when providing a comparison output of two input signals. The comparator contains a transistor configured in a source/emitter follower configuration, and operates in the saturation region for substantially the entire range of strengths of the input signals. As a result, the comparator presents a substantially constant load to the input signals. When incorporated in circuits such as a pipeline ADC, the comparator may substantially eliminate errors due to non-linear loads.

Comparator architecture

A delay locked loop (DLL) circuit in which situations of lock to multiple periods of a reference signal is determined by a lock detector using dummy delay elements and a duty cycle correction circuit (DCC). The lock detector, the dummy delay elements and the delay control circuit are used in a path parallel to the delay elements which generate the desired delayed signals having different delays in relation to the reference signal. Due to the use of the parallel path, the throughput performance of the DLL circuit is not impeded. In an embodiment, separate charge pumps are used by a phase comparator and the lock detector used in the parallel path.

Generating multiple delayed signals of different phases from a reference signal using delay locked loop (DLL)

A switched-capacitor circuit for use in analog-to-digital conversion samples an input signal with respect to a reference voltage such that it significantly reduces a DAC settling time interval during each bit trial. In one exemplary embodiment, the switched-capacitor circuit having first and second groups of capacitor banks is coupled to a first input of a comparator and to a control circuit which provides control signals such that during a switching sequence, an equal value of capacitance is selected from each of the first and second groups of capacitor banks to reduce the DAC settling time interval, thereby improving the conversion rate.

Method and apparatus for segmented, switched analog/digital converter

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Bengaluru, India

Ramesh Kumar Singh