An apparatus converts m-bit digital data having a scale factor of K.sub.1 to n-bit digital data having a scale factor of K.sub.2. The apparatus comprises a digital to analog converter which receives the m-bit digital data, for outputting a first analog signal representative of a value associated with the m-bit digital data. An amplifier receives the first analog signal multiplies it by a factor, and outputs a second analog signal. The factor of the amplifier is K.sub.2 /K.sub.1, such that the second analog signal has a value with the scale factor of K.sub.2 associated therewith. An analog to digital converter receives the second analog signal, and converts the second analog signal to the n-bit digital data. The n-bit digital data has the scale factor of K.sub.2 associated therewith, the value representative of the n-bit digital data being essentially equal in the example of the present application to the value representative of the m-bit digital data, however, this is not always a requirement.