The AD639 is an analog "trigonometric microsystem" on a single silicon chip, packaged in a 16-pin DIP. From a differential voltage input, representing an angle, (20mV/°), it can be pin-programmed to generate a voltage output, accurately determined by any of the standard functions—sine, cosine, tangent, secant, cosecant, and cotangent—as well as some lesser-known variants, such as the versine and exsecant, plus a corresponding set of inverse functions. Read full article