An image sensor and a manufacturing method thereof are provided, so that the warp or the distortion is not caused even if there is the thermal expansion difference or the thermal contraction difference in the longitudinal direction between the linear illuminating device and the frame. The phase-locked loop circuit comprises a phase detector, a proportional charge pump, a decimator, an integral charge pimp, and a voltage-controlled oscillator. The feedback value or the reference value or both are generated using noise shaping.