The design and implementation of a low temperature coecient bandgap reference voltage source
M.Y. Ren, B. Yu & Z.P. Jiang · 2015
VBG is a bandgap voltage of silicon. It can be seen by formula (2) that VBG is having a negative temperature coefficient. Proportional to the absolute temperature difference between the emitter voltage of - transistors operate at different current densities, their base. If two similar transistors (IS1 = IS2) bias collector current respectively nI0 and I0, and their base currents are ignored, then equation (1): ∆ VBE exhibits a positive temperature coefficient, and the temperature coefficient is temperature-independent constant. The weighted positive voltage, the negative temperature coefficient of the sum, can get an approximate temperature-independent reference voltage. Here direct output reference voltage. By bipolar transistors Q1, Q2 and R1 form a current proportional to absolute temperature: I V N R T ln( ) = (3) ( )= + ⋅ ⋅V V R R (4) It is obtained by analyzed the ratio of resistor R2 and R1.