This paper presents a novel design methodology of micropower noncritical clock generator for charge pump circuits. Embedded clock generator circuit requires careful attention in terms many issues: topology choices, component sizes, power dissipation and signal voltage values. This paper also presents comparisons and performance optimization of microwatt clock generators using SPICE simulator. Additionally a contour graph approach is developed to find relevant parameters value in order to minimize the power consumption and the chip area. The circuit design was implemented on standard 0.35 μm Si CMOS process. The active area dimensions are 42 μm*25 μm. Consistent results were obtained between experimental results and transient simulations. In comparison to previous papers, under low-voltage constraints, interesting measured circuit consumption was observed: 1.15 μW from 1 V.