The AD639 is a high accuracy monolithic function converter which provides all the standard trigonometric functions and their inverse via pin-strapping. Law conformance and total harmonic distortion surpass the previously attained using analog shaping techniques. Speed also exceeds that possible using ROM look-up tables and a DAC; in the sine mode, bandwidth is typically 1.5MHz. Unlike other function synthesis circuits, the AD639 provides a smooth and continuous sine conformance over a range of -500° to +500°. A unique sine generation technique results in 0.02% law conformance errors and distortion levels of -74dB in triwave to sinewave conversion.