A nanopower subthreshold bandgap reference with 30ppm/°C from -30°C to 150°C has been implemented in 0.18μm CMOS. This design is based on weighted ΔVGS and is free of resistors. The major advantage of this design is that with nanopower consumption, the temperature range is extremely wide. To achieve high performance of subthreshold bandgap operating in high temperature (above 80°C), a leakage current elimination technique which enables subthreshold bandgap operate properly until 150°C was proposed. Such modification does not require additional die area and power consumption. This topology can also generate multiple reference voltages whose values are integer times of the minimum reference voltage. The line regulation of the reference voltage is 0.677mV/V when the supply voltage is increased from 1 V to 2.5 V. The core circuit consumes 46nW at IV at room temperature. The active area occupies 0.0036mm2.