A system for controlling a slew rate of a signal, such as used in an imaging device, comprises a counter for measuring a duration that the signal drops from a maximum voltage to a predetermined reference voltage; a register for retaining a desired duration that the signal drops from the maximum voltage to the predetermined reference voltage; and a comparator for comparing the measured duration to the desired duration, the comparator being operative of a current source for the signal. An anti-oscillation circuit prevents the system from oscillating between two discrete durations.