Bandgap Voltage Reference
Chi‐Wah Kok, Wing‐Shan Tam · 2012
The energy gap of the silicon is a temperature dependent function, where the temperature dependency is a result of the lattice expansion and contraction in response to the temperature, the temperature coefficient of the energy gap of the silicon is so small in the temperature region of interest that the Widar bandgap voltage reference circuit is widely used to obtain a stable reference voltage for a large variety of CMOS circuits. Almost all the necessary knowledge for the design and implementation of temperature independent reference voltage circuit are acquired by studying the opamp based ß-multiplier bandgap voltage reference circuit. The theory, design, and implementation of all the major circuit blocks of the opamp based ß-multiplier bandgap voltage reference circuit are presented in detail, together with a layout example of each circuit block, where the circuit blocks are divided into opamp, current mirror, bipolar transistors, resistor network, and startup circuit. Controlled Vocabulary Terms bipolar transistors; CMOS integrated circuits; current mirrors; reference circuits; resistors; silicon