Reference compensating circuit in TL431
Zhao Shi-fan · Modern Electronics Technique · 2014
In the TL431 circuit with bipolar technology,in order to improve the stability and accuracy of the output reference voltage of the TL431 circuit,the temperature compensation and accuracy compensation of the bandgap reference source are carried out with the exponential curvature and secondary-order nonlinear compensation obtained by adjusting the resistance,and accuracy compensation by weighted resistance correction network based on traditional bandgap reference circuit. The adjusted temperature coefficient of 24.77ppm/℃ was obtained by circuit simulation. The paramter test of the chip whose accuracy reference circuit was adjusted was executed. The analysis indicates that the yield exceeds 96% in the accuracy range of ±0.5%. This compensating bandgap reference circuit in TL431 can get the design index of low temperature coefficient and high accuracy.