A ramp generator is provided that includes an amplifier, first and second transistors, a variable resistive load having a control electrode, and a capacitor. The amplifier has an inverting input that receives a first reference voltage, and an output connected to the gate of the first transistor. The first transistor has a source connected to a second reference voltage, and a drain connected to the non-inverting input of the amplifier and also to the variable resistive load. The second transistor mirrors the current of the first transistor so as to charge the capacitor, which is periodically discharged by a discharging circuit. In one embodiment, the generator further comprises a comparator, a filter, and an integrator that control the variable resistive load so as to generate a slope having characteristics that are noticeably independent from dispersion, from manufacturing methods, and temperature.