Abstract: Input codes are sequenced at a lower-resolution linear DAC and the output is converted to a linear current waveform. A first of two interconnected analog current multipliers multiplies the linear current by itself and by the inverse of a first constant current source to create a quadratic current output. A second current multiplier multiplies the quadratic output current by the linear current and by the inverse of a second constant current source to generate a cubic current output. The quadratic and cubic currents are subtracted from the linear current to generate an approximation of the first 180 degrees of a sine wave current. Alternate (pi to 2*pi) positive-going one-half sine waves may be polarity reversed to create a complete positive-going and negative-going sine-shaped electrical current of higher resolution than is available from a sine DAC of resolution equivalent to that of the lower-resolution linear DAC.

Abstract: Input codes are sequenced at a lower-resolution linear DAC and the output is converted to a linear current waveform. A first of two interconnected analog current multipliers multiplies the linear current by itself and by the inverse of a first constant current source to create a quadratic current output. A second current multiplier multiplies the quadratic output current by the linear current and by the inverse of a second constant current source to generate a cubic current output. The quadratic and cubic currents are subtracted from the linear current to generate an approximation of the first 180 degrees of a sine wave current. Alternate (pi to 2*pi) positive-going one-half sine waves may be polarity reversed to create a complete positive-going and negative-going sine-shaped electrical current of higher resolution than is available from a sine DAC of resolution equivalent to that of the lower-resolution linear DAC.