A low-power low-voltage MOSFET-only voltage reference

A low-power low-voltage MOSFET-only voltage reference featuring very good temperature stability and referred to the positive power supply is proposed. It compensates for the temperature dependence of a gate-to-source voltage of an MOS transistor working in the weak inversion region with a proportional-to-absolute-temperature voltage generated by a pair of MOS devices operating in the same region. The circuit, designed for a 0.35-/spl mu/m (0.18-/spl mu/m in the memory array) CMOS flash memory technology, can operate with supply voltage as low as 1 V and draws a current of 3 /spl mu/A. The simulated variation of the reference voltage is within 0.2% over the range from -20 to 80/spl deg/C.