A 0.75V 30.1 ppm/°C 300nW Bandgap Reference and Low Power Low-dropout Regulator with Hybrid form of Resistors as Size Reduction Technique

Abstract

This paper proposes a low-power bandgap reference(BGR) and low-dropout regulator(LDO) circuit that apply size reduction technique. Using stacked-MOS transistors in triode region as resistors occupies less layout area than poly resistors with the same resistance. Although the resistance of MOS transistors has wider PVT variations than that of poly resistors, The hybrid form of both MOS resistors and poly resistors can have acceptable PVT variation of resistance with noticeable size reduction. The proposed BGR and LDO with the size reduction technique have the layout size of 0.034mm2 total, which could be 0.050mm2 with poly resistors only. The layout size saving effect is 0.016mm2, which is 31.36% of the total. The proposed BGR produces 0.75V reference voltage with temperature coefficient of 30.1[ppm/°C] over temperature range of −40°C∼125°C. The power consumption is 300nW with layout size of 0.025mm2. The proposed LDO has 0.9V output voltage with input voltage of 2∼3.6V. The operating current is 260nA. The layout size of the LDO is 0.009mm2.