Abstract: A CMOS voltage reference,which is based on VGS and ΔVGS in the weak inversion region,has been designed and implemented in standard 0.6μm CMOS technology.No diodes and parasitic bipolar junction transistors (BJTs) are used.The proposed voltage reference uses a current-mode topology by summing a PTAT current and a CTAT current into a resistor to generate the required reference voltage.It can also provide more than one reference voltage output,which is quite suitable for systems requiring many different reference voltages simultaneously.The occupied chip area is 0.023mm2.The operation supply voltage is from 2.5 to 6V,and the maximum supply current is 8.25μA.The designed three different outputs are respectively about 203mV,1.0V,and 2.05V at room temperature when the supply voltage is 4V.The circuit achieves a temperature coefficient of 31ppm/℃ in the temperature range of 0 to 100℃ and an average line regulation of ±0.203%/V.The voltage reference has been successfully applied in a white LED backlight driver chip.

Key words: CMOS voltage reference, CTAT current, PTAT current, temperature coefficient, weak inversion region