US Patent 7227485 Waveform control circuit

The waveform conform control circuit includes a waveform generator, an amplitude adjustment device and an offset device. The waveform generator produces a current waveform. The amplitude adjustment device receives amplitudes amplitude data and produces a predetermined scale factor which is applied to the basic current waveform to produce a scaled current waveform. The offset device is a digital to analog converter for receiving offset data and producing a predetermined scale value that is added to the scaled waveform to produce a final current waveform. A method a digitally generated waveform is also disclosed. An offset circuit using current steering digital to analog and a current mirror is also disclosed.