학술논문

A 12-b 18-GS/s RF Sampling ADC With an Integrated Wideband Track-and-Hold Amplifier and Background Calibration
Document Type
Periodical
Source
IEEE Journal of Solid-State Circuits IEEE J. Solid-State Circuits Solid-State Circuits, IEEE Journal of. 55(12):3210-3224 Dec, 2020
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Computing and Processing
Calibration
Radio frequency
Switches
Clocks
Bandwidth
Pipelines
Power demand
Analog-to-digital converter (ADC)
background calibration
DAC calibration
digital assistance
interleaved
non-linear calibration
pipeline
reference calibration
RF sampling
sample-and-hold
sample-and-hold amplifier (SHA)
track-and-hold
track-and-hold amplifier (THA)
Language
ISSN
0018-9200
1558-173X
Abstract
We discuss a 12-b 18-GS/s analog-to-digital converter (ADC) implemented in 16-nm FinFET process. The ADC is composed of an integrated high-speed track-and-hold amplifier (THA) driving up to eight interleaved pipeline ADCs that employ open-loop inter-stage amplifiers. Up to 10 GS/s, the THA operates at the full sampling rate using a non-interleaved single sample network, thereby eliminating the interleaving sampling time and bandwidth mismatch. Above 10 GS/s, the THA is programmed to use two ping-ponged, or an optional (2 + 1) randomized, sample networks to spread the residual post-calibration interleaving spurs in the noise floor. The THA enables an input bandwidth of 18 GHz and employs dither injection and optional pseudorandom chopping. In the pipeline stages, dither-based background calibration detects and corrects gain, settling, memory, and kick-back errors. New dither-based background calibration algorithms are employed to detect and correct the arbitrary non-linearity in the form of integral non-linearity (INL) breaks and harmonic distortion up to the fifth order in the THA and in the references, DACs, and inter-stage open-loop amplifiers of the pipeline ADCs. Moreover, new dither-based background calibration is implemented to detect and correct the chopping non-idealities, memory errors, interleaving mismatches, and order-dependent randomization errors. Compared to the fastest state-of-the-art with similar performance, this ADC achieves 80% higher sample rate and 2.4 $\times $ higher input bandwidth, and incorporates a THA that supports a 3.3 $\times $ higher non-interleaved sample rate.