Driver circuits are described for driving one or more light emitting diodes. A driver circuit may comprise an interface configured to receive control signals from a processor and a signal generator configured to generate pulse modulation (PM) signals based on the control signals, wherein the PM signals define phase shifts. In some examples, the signal generator is configured to: determine whether the control signals indicate a phase shift change; and in response to determining that the control signals indicate a phase shift change, terminate a current PM signal at a beginning of a PM period, and generate a new PM signal in the PM period, wherein the new PM signal includes the phase shift change. In other examples, termination may be avoided in some situations, for example, upon determining that a new phase shift is not sufficiently less than a previous phase shift.