Abstract: This paper presents an integrated power management unit (PMU) for a battery-operated wireless endoscopic system.This PMU is integrated with a baseband chip in standard 0.18μm CMOS technology,promising low cost,ease in PCB design,and a minimum in system size.The optimized power supply architecture is derived from comparison.Circuits of sub blocks are presented in detail.As a result,only five small off-chip capacitances are required by PMU with an overall quiet current consumption of less than 100μA.Moreover,a digital calibration method is adopted to alleviate the effect of process variation.The achieved performance is also demonstrated with corresponding measurement results.

Key words: power management unit, LDO, charge pump, oscillator, integration, wireless endoscopic system