Low Voltage Current Reference with Temperature and Process Variation Compensation

A. Bendali and Y. Audet (Canada)


-- Current reference, bandgap reference,low voltage, transimpedance amplifier.


This paper proposes a new 1V-voltage CMOS current reference which provides a small dependence of the output current on temperature and process variation. The proposed topology is based on a current-mode bandgap structure that uses a transimpedance amplifier. In order to obtain a small sensitivity of the output current with respect to changes in process parameters and temperature, a threshold voltage (VTH) compensation technique of an output nMOS transistor is used. It produces not only a mutual temperature compensation of mobility and VTH variations, but also reduces the effect of VTH process variation on the output current. SPICE simulations using the TSMC CMOS 0.18m confirms the theoretical analysis. Variations of the output current over a typical temperature range (-40 to 100 C) were simulated to be less than 0.9%, while output changes due to process variation is less than 1%.

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