Vehicle charger

1. A vehicle charger, comprising:

a power supply device configured to change an input voltage into a voltage required to charge a portable device and output the changed voltage;

a communication module configured to receive a communication signal from the portable device, the communication signal including information indicating at least one of a voltage and a current, required to charge the portable device;

a reference changing unit configured to generate at least one of a reference voltage and a reference current based on the at least one of the voltage and the current indicated in the communication signal;

a compensator configured to generate a compensation signal based on a result obtained by comparing the at least one of the reference voltage and the reference current with at least one of a sensed voltage and a sensed current, which are obtained by sensing at least one of an output voltage of the power supply device and a current supplied from the power supply device to the portable device;

a controller configured to generate a gate driving signal according to the compensation signal; and

a gate driver configured to generate a gate voltage for controlling switching operation of the power supply device according to the gate driving signal.

2. The vehicle charger of claim 1 , wherein in changing the input voltage the power supply device is configured to step up or step down the input voltage according to the gate voltage.

3. The vehicle charger of claim 1 , wherein the compensator is configured to generate the compensation signal by compensating for a difference between the sensed voltage and the reference voltage.

4. The vehicle charger of claim 1 , wherein the compensator is configured to generate the compensation signal by compensating for a difference between the sensed current and the reference current.

5. The vehicle charger of claim 1 , comprising a chip including at least the communication module, the reference changing unit, the compensator, and the controller.

6. The vehicle charger of claim 1 , comprising a chip including at least the communication module, the reference changing unit, the controller, and the gate driver.

7. The vehicle charger of claim 1 , comprising a chip including at least the communication module, the reference changing unit, the controller, and a switching unit of the power supply device.

8. The vehicle charger of claim 7 , wherein the chip further comprises the gate driver.

9. The vehicle charger of claim 8 , wherein the chip further comprises the compensator.

10. The vehicle charger of claim 7 , wherein the chip further comprises a power transmitting unit of the power supply device.

11. The vehicle charger of claim 1 , wherein the vehicle charger is configured to stop operation of the power supply device when the vehicle charger detects pollution of a USB cable terminal through which the power supply device is connected to the portable device or a connection terminal of the portable device, wherein the pollution is detected by the vehicle charger as a change in impedance between USB cable terminals.

12. The vehicle charger of claim 11 , further comprising a protector configured to generate a protection signal when the protector detects the pollution of the USB cable terminal through which the power supply device is connected to the portable device or the connection terminal of the portable device.

13. The vehicle charger of claim 12 , comprising a chip including at least the protector, the communication module, the reference changing unit, and the controller.

14. The vehicle charger of claim 13 , wherein the chip further comprises the switching unit of the power supply device.