This paper presents a freewheel-charge-pump-controlled design for a single-inductor multiple-output (SIMO) DC-DC Converter. By applying the freewheel-charge-pump-controlled (FCPC) technique, the freewheel switching time is reused, and two extra charge-pump outputs are provided by time recycling, with no cost in time sequences. The converter has two step-up outputs and two charge-pump outputs that can be higher or lower than the input supply. The converter utilizes a 1 μH inductor, 4.7 μF charge-pump capacitors and 33 μF output capacitors at a frequency of 1 MHz. The proposed converter shows low cross-regulation and achieves a maximum loading current of 70 mA. Fabricated in a 0.18-μm CMOS process, the proposed circuit occupies 1.3 × 1.3 mm2. Experimental results demonstrate that the converter successfully generates four well-regulated outputs with a single inductor. The supply voltage ranged from 1.6 to 2.5 V and the load regulation performance was 0.08, 0.05, 1.7, and 1.9 mV/mA for VO1, VO2, VO3 and VO4, respectively.
- Charge-pump regulator
- Freewheel switching
- Freewheel-charge-pump-controlled (FCPC)
- Pseudo-continuous conduction mode (PCCM)
- Single-inductor multiple-output (SIMO) converter