Voltage converter for simulating inductor current control

A voltage converter for simulating inductor current control, used to convert an input voltage into an output voltage, and the voltage converter comprising:

• a power level circuit having a first switch, a second switch, a third switch, a fourth switch, and an inductor, wherein an end of the inductor is coupled between the first switch and the second switch and another end of the inductor is coupled between the third switch and the fourth switch;
• a gate driver coupled to the power level circuit, periodically controlling the first switch, the second switch, the third switch, and fourth switch according to a plurality of operation signals to charge or discharge the inductor in a buck mode or in a boost mode, and generating the output voltage according to an inductor current flowing through the inductor;
• a control circuit coupled between the power level circuit and the gate driver, generating a feedback error signal related to the output voltage, and generating the operation signals according to the feedback error signal and a ramp signal related to the inductor current;
• and
• an inductor current ramp generator coupled to the control circuit and the power level circuit;
• wherein when the gate driver drives the power level circuit in the buck mode to charge the inductor, the inductor current ramp generator increases the ramp signal according to one of the operation signals controlling the first switch, the second switch, the input voltage and the output voltage, to simulate the inductor current;
• wherein when the gate driver drives the power level circuit in the buck mode to discharge the inductor, the inductor current ramp generator decreases the ramp signal according to one of the operation signals controlling the first switch, the second switch, the input voltage and the output voltage, to simulate the inductor current;
• wherein when the gate driver drives the power level circuit in the boost mode to discharge the inductor, the inductor current ramp generator decreases the ramp signal according to one of the operation signals controlling the third switch, the fourth switch, the input voltage and the output voltage, to simulate the inductor current;
• wherein when the gate driver drives the power level circuit in the boost mode to charge the inductor, the inductor current ramp generator increases the ramp signal according to one of the operation signals controlling the third switch, the fourth switch, the input voltage and the output voltage, to simulate the inductor current;
• wherein an end of the first switch receives the input voltage, another end of the first switch connects to ground through the second switch, an end of the fourth switch connects to ground through the third switch, and the inductor generates the output voltage through another end of the fourth switch, wherein the inductor current ramp generator includes:
• a discharging switch connected in series with a discharging current source, wherein a discharging current of the discharging current source is related to the output voltage with a first rate;
• a charging switch connected in series with a charging current source, wherein a charging current of the charging current source is related to the input voltage with a second rate;
• and
• a capacitor connected in parallel to the discharging current source and the charging current source;
• wherein when the gate driver drives the power level circuit to charge the inductor in the buck mode, the discharging switch maintains conduction according to a high-level, the charging switch conducts according to one of the operation signals controlling the first switch and the second switch, the charging current source charges the capacitor and the discharging current source discharges the capacitor to generate the ramp signal;
• wherein when the gate driver drives the power level circuit to discharge the inductor in the buck mode, the discharging switch maintains conduction according to the high-level, the charging switch cuts off according to one of the operation signals controlling the first switch and the second switch, and the discharging current source discharges the capacitor to generate the ramp signal.