This paper presents a power management system of the dye-sensitized solar cell (DSSC) for ubiquitous sensor network (USN) applications. The charge pump with a luminance-controlled oscillator regulates the load impedance of the DSSC to track the maximum power point (MPP) under various light intensities. The low drop-out regulator with a hysteresis comparator supplies intermittent power pulses that are wide enough for USN to communicate with a host transponder even under dim light conditions. With MPP tracking, approximately 50% more power is harvested over a wide range of light intensity. The power management system fabricated using $0.13{mu}m$ CMOS technology works with DSSC to provide power pulses of $36{mu}A$. The duration of pulses is almost constant around $80{mu}s$ (6.5 nJ/pulse), while the pulse spacing is inversely proportional to the light intensity.