A controllable lighting device may comprise a drive circuit characterized by one or more cycles and a control circuit configured to control the drive circuit to conduct a load current through a light source of the lighting device. The control circuit may be configured to determine one or more operating parameters of the lighting device during a present cycle of the drive circuit based on a feedback signal indicative of a peak magnitude of the load current conducted through the light source. The control circuit may be able to adjust an average magnitude of the load current conducted through the light source so as to adjust an intensity of the light source towards a target intensity based on the operating parameters.