In this paper, an 8bit CMOS low power, high-speed current-mode folding and interpolation A/D converter is designed with te LG semicon $0.8mu extrm{m}$ N-well single-poly/double-metal CMOS process to be integrated into a portable image signal processing system such as a digital camcoder. For good linearity and low power consumption, folding amplifiers and for high speed performance of the A/D converter, analog circuitries including folding block, current-mode interpolation circuit and current comparator are designed as a differential-mode. The fabricated 8 bit A/D converter occupies the active chip area of TEX>$2.2mm imes 1.6mm$</TEX> and shows DNL of $pm0.2LSB$, INL of <$pm0.5LSB$, conversion rate of 40M samples/s, and the measured maximum power dissipation of 33.6mW at single +5V supply voltage.