Open AccessCalibration of bandgap voltage reference using chopping technique and IIR filter
Author(s) -
Um J.Y.
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2016.1267
Subject(s) - bandgap voltage reference , voltage reference , input offset voltage , voltage divider , voltage , overdrive voltage , cmos , calibration , electronic engineering , materials science , dropout voltage , control theory (sociology) , amplifier , operational amplifier , electrical engineering , physics , engineering , computer science , control (management) , artificial intelligence , quantum mechanics
A calibration scheme is proposed for a bandgap voltage reference. The proposed scheme calibrates an offset voltage of operational trans‐conductance amplifier (OTA) of a bandgap reference which is the critical source of an output‐voltage deviation of the bandgap reference. The proposed calibration is based on a chopping technique which makes an output voltage of OTA modulate. An infinite impulse response (IIR) filter is used to average out the modulated output voltage of OTA. The output voltage of IIR filter is fed into gate node of a Positive‐channel Metal‐Oxide Semiconductor (PMOS) current source which is located in the final output branch. As a result, the output reference voltage becomes insensitive to the offset voltage of OTA. The proposed circuit was verified through Monte‐Carlo simulations by using thick‐oxide transistors in a 0.13 μm CMOS process. In the simulation results, the proposed calibration suppresses the deviation of output reference voltage up to 1.94 mV for the temperature range between −40°C and 125°C. Also, the deviation of output reference voltage is reduced by 24.5 times through proposed calibration.