Abstract
The current study is about a first order bandgap reference circuit (BGR) that makes use of a single stage differential amplifier and a BJT. An external start- up circuit (based on current mirror) is utilised to accelerate transistor switching and avoid non-stable BGR states. The opamp has been developed to provide optimal gain for the BGR. BGR temperature independence was accomplished by superimposing the effects of CTAT and PTAT. Constant voltage generation with temperature change (-40oC to 125oC) has been confirmed using an open source simulation tool (NGSPICE). According to simulation results, the temperature coefficient and starting time of the design were 78.8 ppm/oC and 12s, respectively.
Keywords: - PTAT, Bandgap, PTAT, CTAT, opamp.
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