Precise CMOS band-gap voltage and current references which uses the difference of MOS source-gate voltages to perform efficient curvature compensation are proposed and analyzed. Applying the developed design strategies, band-gap voltage references (BVR) with a temperature drift below 10 ppm/°C and a power-supply drift below 10 ppm/V can be realized. For band-gap current references, both drifts can be under 15 ppm. Experimental BVR chip shows an average drift of 5.5 ppm/°C from -60°C to 150°C and 25 μV/V for supply voltages from 5 to 15 V at 25°C. Due to the use of the novel curvature-compensation technique, the circuit structure of the proposed references is simple and both chip area and power consumption are small.