We report a fully adjustable arbitrary timing generator (ATG) that is based on a multistage time interpolation method. A 3 ps timing adjustment resolution is achieved using a three-stage time interpolation module. The output signal amplitude of the ATG is adjustable, as a current controlled output module is designed to adjust the output voltage of driver circuits. A field programmable gate array is used to realize the main logic of the ATG. A 3.2 ps short term jitter, a pulse width dynamic range from 6.25 ns to 5 s, and an output voltage range between -1 and +5 V are obtained. The arbitrary timing generator can be used in the applications that require high precision timing control and adjustable output capacity.