A regulator circuit for step-up and step-down operation having an input (Vin) connectable to a power source and an output (Vout) connectable to a load, the regulator circuit comprising: an inductor having first and second terminals; a first switch connected between the first inductor terminal and an input terminal; a second switch connected between the second inductor terminal and a node; a first rectifying device connected between the first inductor terminal and the node; a second rectifying device connected between the second inductor terminal and an output terminal (Vout); a sensing element for sensing inductor current connected between the common connection and a node joining the second switch and the first rectifying device; and a control circuit responsive to sensed inductor current for controlling activation and deactivation of at least one of the switches (22, 34) to regulate voltage at the output (Vout) to a preset voltage, wherein the control circuit comprises: a comparator circuitry (54, 56); a logic circuit (46, 50) connected to the comparator circuitry (54, 56) to receive input therefrom; and a switch driver circuitry (48, 49) responsive to the logic circuit (46, 50) for controlling the states of the switches (22, 34), the regulator circuit being characterized in that the comparator circuitry (54, 56) comprises: an error amplifier having a first input for receiving a voltage proportional to the voltage at the output terminal and a second input for receiving a reference potential to produce a difference signal representing the difference therebetween; a differential circuit responsive to the difference signal and the inductor current sensing element, the differential circuit connected to the logic circuit; and wherein the differential circuit comprises a first circuit section for receiving a signal output from the current sensing element and a second circuit section for receiving the signal output from the current sensing element with inverted polarity. an inductor having first and second terminals; a first switch connected between the first inductor terminal and an input terminal; a second switch connected between the second inductor terminal and a node; a first rectifying device connected between the first inductor terminal and the node; a second rectifying device connected between the second inductor terminal and an output terminal (Vout); a sensing element for sensing inductor current connected between the common connection and a node joining the second switch and the first rectifying device; and a control circuit responsive to sensed inductor current for controlling activation and deactivation of at least one of the switches (22, 34) to regulate voltage at the output (Vout) to a preset voltage, wherein the control circuit comprises: a comparator circuitry (54, 56); a logic circuit (46, 50) connected to the comparator circuitry (54, 56) to receive input therefrom; and a switch driver circuitry (48, 49) responsive to the logic circuit (46, 50) for controlling the states of the switches (22, 34), the regulator circuit being characterized in that a comparator circuitry (54, 56); a logic circuit (46, 50) connected to the comparator circuitry (54, 56) to receive input therefrom; and a switch driver circuitry (48, 49) responsive to the logic circuit (46, 50) for controlling the states of the switches (22, 34), the regulator circuit being characterized in that the comparator circuitry (54, 56) comprises: an error amplifier having a first input for receiving a voltage proportional to the voltage at the output terminal and a second input for receiving a reference potential to produce a difference signal representing the difference therebetween; a differential circuit responsive to the difference signal and the inductor current sensing element, the differential circuit connected to the logic circuit; and wherein the differential circuit comprises a first circuit section for receiving a signal output from the current sensing element and a second circuit section for receiving the signal output from the current sensing element with inverted polarity. an error amplifier having a first input for receiving a voltage proportional to the voltage at the output terminal and a second input for receiving a reference potential to produce a difference signal representing the difference therebetween; a differential circuit responsive to the difference signal and the inductor current sensing element, the differential circuit connected to the logic circuit; and wherein the differential circuit comprises a first circuit section for receiving a signal output from the current sensing element and a second circuit section for receiving the signal output from the current sensing element with inverted polarity.