Abstract: A digital frequency synthesizer includes a digital-to-analog (1), a low pass filter (2), and a controllable oscillator (3), where the oscillator output is the synthesizer output. K number of RS flip-flops (101-108) produce error signals which are coupled to the DAC. The S inputs of the flip-flops come from a phase-splitter (8) which is driven by the more-significant bits unit of an accumulator (5) which is clocked by a reference frequency. The R inputs of the same flip-flops get input pulses from a pulse distributor (9) which is driven by the synthesizer output. The frequency resolution can be increased by adding a less-significant bits accumulator (15), coupled to the more-significant bits unit.