Wide input range from 80mV to 3V operation on-chip single-inductor dual-output (SIDO) DC-DC boost converter with self-adjusting clock duty for sensor network applications

An SIDO boost DC-DC converter operating with a wide input voltage range is proposed for sensor network applications. As the input voltage becomes lower, the inductor current is restricted by on-resistance of a driver transistor. Therefore, longer Ton period does not indicate a lager inductor current. In this condition, Ton period for the lowest input voltage operation is determined as the inductor current reaches 85% of its ideal value. The converter should operate in a continuous conduction mode (CCM) to obtain the maximum power from the input. Toff period is set by feed forward control from Ton period to sustain the output voltages. A test chip fabricated by a 190nm CMOS technology operates at the input voltage range from 80mV to 3V with maintaining the two output voltages of 3V and 5V, respectively. This means that the power of 625μW is substantially supplied from the input of 80mV for inner circuits.