A low power successive approximation analog-todigital converter is presented operating at 1.2 V supply. The circuit has been designed in a 0.13 gm standard CMOS technology. The power consumption while converting is 13gW, and in standby mode the power is reduced to 5.8gW. The resolution is programmable between 1 to 8 bits. It can work from 500Hz up to 50KHz clock frequencies.