A Fast Transient Digitally Assisted Flash-Based Modular LDO for Sensor Nodes in WBAN

In this paper, a dual-mode digitally assisted Low dropout regulator (LDO) based on battery level is proposed with fast transient response specifically targeted for sensor nodes in wireless body area network (WBAN). Digital low dropout regulators are suitable in PMU for providing low voltage requirements under different load condition. The proposed LDO provides regulated voltage in order to achieve dynamic voltage scaling for the two specific modes. It achieves the primary control word through a flash-based architecture with minimal clock cycles in a particular mode, once load transient shifts output voltage beyond a desired range. The proposed LDO achieved 0.7 V output voltage while simulated in 180nm CMOS process resulting 96% current efficiency at load current of 100 µA as well as at 10 mA. It achieves fast settling time of 30 ns; making it feasible for real time application in WBAN.