Design Of Low Supply Voltage Bandgap Reference

Bandgap reference is widely used in both analog and mixed-signal integrated circuit, such as A/D and D/A etc. . As feature size in integrated circuit shinks, the supply voltage decreases too. When the supply voltage is lower than 1.5V, tranditional bandgap reference circuits can not work, then a new structure bandgap reference circuit arises which can work under the low supply voltage. Moreover, with the rapid development of high accurate systems, portable devices and mixed-signal integrated circuits, higher requirements have been proposed to temperature coefficient, low power dissipation design and high PSRR of bandgap reference. All these will give greater chanllenges to the design of low supply voltage bandgap reference.Firstly, this paper introduces the history and research, the specification and fundamental theory of bandgap reference. Then, according to the specification, based on TSMC 0.13μm 1P8M sdandard CMOS process, this paper implements a low voltage current mode bandgap reference, including front end circuit design, layout design and test. According to layout simulation results, the output voltage varies 0.65mV over the range from -40 oC to 130 oC, and the temperature coefficient is 5.46ppm/ oC; the output voltage varies 0.8mV when supply voltage changes from 1.05V to 1.5V, and the PSRR is–55.76dB at low frequency(1kHz). The test results show a 0.4mV variation when supply voltage changes from 1.1V to 1.3V, and a 3.2mV(44.4 ppm/ oC) variation from 27 oC to 130 oC. The circuit achieves design specification, and has good performance.