A ramp generator includes a plurality of switched current sources coupled in parallel between a resistor and ground. A digital ramp control signal generator includes a counter to generate a ramp control signal in response to a clock signal. Each bit of the ramp control signal is coupled to control switching of a respective one of the plurality of switched current sources to generate a ramp signal at an output of the ramp generator. The digital ramp control signal generator is coupled to receive a reset signal to zero the ramp control signal. The digital ramp control signal generator is further coupled to receive a set bits signal to initialize the ramp signal to a preset value after every reset of the ramp control signal to add a DC offset compensation current determined by the preset value to the ramp signal.