Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications

Designing an AIoT system with low standby power and high efficiency has become increasingly challenging. The AIoT system is an IoT device with artificial intelligence. A typical AIoT system is an always-on portable ECG monitoring system with AI algorithm to detect irregular event. ADC is the bottlen...

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Bibliographic Details
Main Author: Chen, Ruicong
Other Authors: Anantha P. Chandrakasan
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/139133
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author Chen, Ruicong
author2 Anantha P. Chandrakasan
author_facet Anantha P. Chandrakasan
Chen, Ruicong
author_sort Chen, Ruicong
collection MIT
description Designing an AIoT system with low standby power and high efficiency has become increasingly challenging. The AIoT system is an IoT device with artificial intelligence. A typical AIoT system is an always-on portable ECG monitoring system with AI algorithm to detect irregular event. ADC is the bottleneck of the current AIoT systems as it bridge the gap between analog world and digital computation. To address the challenge, this thesis presents a SAR ADCs with two modes, activityscaling and direct hybrid Encoding for signed expressions. In the activity-scaling mode, the proposed ADC can finish the conversion in just one cycle in the optimal case compared with N cycles for typical SAR. In the direct hybrid encoding for signed expressions (HESE) mode, it directly provides hybrid encoding for signed expressions which paves the way for high efficient digital inference. The proposed ADC has two thresholds. The activity-scaling mode has an initial guess and takes two steps per cycle to approach the sampled input until overshoot. After that, it performs a ternary search to the LSB. The direct hybrid encoding for signed expressions mode places one of the thresholds at the normal binary conversion threshold and the other for two bits look ahead to produce one-pass encoding. A proof-of-concept SAR ADC has been designed in 65nm CMOS technology.
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spelling mit-1721.1/1391332022-01-15T03:12:50Z Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications Chen, Ruicong Anantha P. Chandrakasan Hae-Seung Lee Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Designing an AIoT system with low standby power and high efficiency has become increasingly challenging. The AIoT system is an IoT device with artificial intelligence. A typical AIoT system is an always-on portable ECG monitoring system with AI algorithm to detect irregular event. ADC is the bottleneck of the current AIoT systems as it bridge the gap between analog world and digital computation. To address the challenge, this thesis presents a SAR ADCs with two modes, activityscaling and direct hybrid Encoding for signed expressions. In the activity-scaling mode, the proposed ADC can finish the conversion in just one cycle in the optimal case compared with N cycles for typical SAR. In the direct hybrid encoding for signed expressions (HESE) mode, it directly provides hybrid encoding for signed expressions which paves the way for high efficient digital inference. The proposed ADC has two thresholds. The activity-scaling mode has an initial guess and takes two steps per cycle to approach the sampled input until overshoot. After that, it performs a ternary search to the LSB. The direct hybrid encoding for signed expressions mode places one of the thresholds at the normal binary conversion threshold and the other for two bits look ahead to produce one-pass encoding. A proof-of-concept SAR ADC has been designed in 65nm CMOS technology. S.M. 2022-01-14T14:51:54Z 2022-01-14T14:51:54Z 2021-06 2021-06-24T19:19:50.457Z Thesis https://hdl.handle.net/1721.1/139133 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Chen, Ruicong
Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title_full Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title_fullStr Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title_full_unstemmed Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title_short Activity-Scaling SAR with Direct Hybrid Encoding for Signed Expressions for AIoT Applications
title_sort activity scaling sar with direct hybrid encoding for signed expressions for aiot applications
url https://hdl.handle.net/1721.1/139133
work_keys_str_mv AT chenruicong activityscalingsarwithdirecthybridencodingforsignedexpressionsforaiotapplications