Patent ID: 7271632

Claim:
A ramp generator comprising: an amplifier including an inverting input, a non-inverting input, and an output, the inverting input receiving a first reference voltage; a first transistor including a gate electrode, a source electrode, and a drain electrode, the gate electrode being connected to the output of the amplifier, the source electrode being connected to a second reference voltage, and the drain electrode being connected to the non-inverting input of the amplifier; a variable resistive load comprising a resistive circuit and a control electrode, the resistive circuit being connected between a third reference voltage and the drain electrode of the first transistor; a load capacitor; a second transistor mirroring the current of the first transistor, the second transistor being connected to the load capacitor so as to generate a copy current for charging the load capacitor; a discharging circuit for discharging the load capacitor; a comparison block including an input coupled to the load capacitor, the comparison block outputting a comparison signal; a filtering block receiving the comparison signal, performing low-pass filtering, and outputting a filtered signal; and an integrating block receiving the filtered signal and outputting an integrated value of the filtered signal, the integrated value being supplied to the control electrode of the variable resistive load.