Analysis and Design of Sub-Threshold R-MOSFET Tunable Resistor

Apisak WORAPISHET  Phanumas KHUMSAT  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E92-C   No.1   pp.135-143
Publication Date: 2009/01/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E92.C.135
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Electronic Circuits
Keyword: 
MOSFET resistor,  R-MOSFET resistor,  sub-threshold techniques,  low voltage techniques,  

Full Text: PDF(1.4MB)>>
Buy this Article




Summary: 
The sub-threshold R-MOSFET resistor structure which enables tuning range extension below the threshold voltage in the MOSFET with moderate to weak inversion operation is analyzed in detail. The principal operation of the sub-threshold resistor is briefly described. The analysis of its characteristic based on approximations of a general MOS equation valid for all regions is given along with discussion on design implication and consideration. Experiments and simulations are provided to validate the theoretical analysis and design, and to verify the feasibility at a supply voltage as low as 0.5 V using a low-threshold devices in a 1.8-V 0.18 µm CMOS process.