Design Of CMOS Bandgap Reference Source

The voltage reference source, which provides high precision voltagereference for the other functional modules, is one of the key modules ofthe analog circuits. The output of the voltage that reference sourcerequires is very stable, and has little relationship with external powersupply voltage, temperature and technology. The development ofreference source is introduced. The basic circuit structure, workingtheory and performance indicators of bandgap circuit, which is a commonvoltage reference source form, are discussed in detail. On the basis, twodifferent emphases of bandgap circuits are designed, and the layout of thesecond circuit is provided.The emphasis of the first circuit is on high performance. The circuitpresents an extremely low temperature coefficient over a very widetemperature range through the second-order temperature compensationmethod. Based on TSMC0.35μm process simulation, the results showtemperature coefficients as low as3.9ppm/℃over a temperature range of165℃(-15℃to150℃). It’s a very low temperature coefficient andexcellent performance.The emphasis of the second circuit is on application. The structureconsists of a simple start-up circuit, Miller two stage amplifier and thecore circuit. Based on the UMC0.18μm process simulation, the resultsshow as follows: in the temperature range of125℃(0℃to125℃)temperature coefficient is9.22ppm/℃, and at10KHz the power supplyrejection ratio is still80dB. This performance can fully meet therequirements of practical applications. And the layout of the circuits isgiven in Chapter5.