A Collection of Contemporary Research Articles in Electronics, Communication & Computation- Book ISBN- 978-81-948050-7-6

Authors: Ankur Sah, Yalamanchili Vahini, Basanta Bhowmik

Abstract: The present paper concerns about a ï¬rst order bandgap reference circuit (BGR) employing a single-stage differential ampliï¬er and BJT. An external start-up circuit (based on the current mirror) is used to expedite the transistor switching faster and to avoid the non-stable state of BGR. The opamp has been designed to offer optimum gain suitable for the BGR. Temperature independence of BGR was achieved by superposition of the effect of CTAT and PTAT. Generation of constant voltage with temperature variation (-40oC to 125oC) has been conï¬rmed through an open-source simulation tool (NGSPICE). The simulation study reveals that the temperature coefï¬cient and the start-up time of the design were 78.8 ppm/oC and 12µs, respectively.

Keywords: Bandgap, PTAT, CTAT, opamp.