As described above, the quantizer degrades the signal if its
(peak-to-peak) amplitude is above an upper bound . The minimum
change in signal amplitude that can be expressed is limited by the
quantization step . Thus a given quantizer operates over a limited
range of input voltage amplitude called its *dynamic range*. The
Dynamic range of a quantizer is usually defined by the ratio of the power of
a sinusoidal signal with peak-to-peak amplitude = to the variance
of the quantization noise. For an ideal quantizer with uniform quantization
the dynamic range is
. Thus the dynamic range is larger
if the number of bits used for quantization is larger.