A DPWM (1) has a locked loop (4) which receives an input clock signal and provides an out-of-phase delayed clock at the output of each cell in the loop (35). A multiplexer (5) selects one of the cell outputs at any one time. This allows the DPWM (1) to have a greater resolution which would otherwise be achieved with the same input clock. The resolution is further increased using an interpolator. A programmable module (2) has a control block (20) which interfaces with external CPU and DSP hosts and transmits programmed parameters to finite state machine controllers (15), each providing an independent output.