Improvement of quantization errors that arise in a delay line with finite
resolution. A direct digital synthesizer (DDS), which contains a
numerically controlled oscillator (NCO) and a digital-to-phase converter
(DPC), is placed in the feedback loop of a phase locked loop (PLL). The
DDS is used as a fractional divider of the voltage controlled oscillator
(VCO) frequency, such that the reference frequency of the DDS is made
variable. Alignment of the edges provided by the DDS delay line may then
be adjusted. Mismatch errors in the DDS delay line are reduced by
utilizing independently tunable delay elements.