US Patent 8183903 Signal interpolation methods and circuits

An interpolation circuit for comparing an input voltage signal with an interpolated reference signal derived from a first reference voltage signal and a second reference voltage signal may include a transconductive circuit configured to generate a first differential current signal proportional to a difference between the first reference voltage signal and the input voltage signal and a second differential current signal proportional to a difference between the second reference voltage signal and the input voltage signal, an intermediate circuit configured to generate a third differential current signal, and a transinductive circuit configured to generate an output voltage signal having a first polarity if a value of the input voltage signal is greater than a value of the interpolated reference signal and a second polarity if the value of the input signal is less than the value of the interpolated reference signal.