An ultra-low power voltage regulator for wireless sensor nodes

This paper presents an ultra-low power voltage regulator used for low power wireless sensor nodes. As the input conditions for these types of regulators can be quite different in terms of voltage range and transient speed, the introduced architecture is designed to be almost insensitive to these variations. Even if the pass device is formed by an NMOS transistor, low-dropout operation is possible by the utilization of a charge pump. The focus is on reducing the energy consumption of the regulator while keeping the robustness high. The regulator does not need an external compensation device. The circuit, implemented in a 0.13 μm CMOS process, generates the supply voltage for an ultra-low power temperature sensor and an ADC. Implementation and experimental results are discussed.