Patent ID: 7336057

Claim:
A DC/DC converter comprising: a boost converter that boosts an input voltage in accordance with a first control signal; an insulated converter that converts an output of the boost converter in accordance with a second control signal; a current sensor that detects an output current of the insulated converter; a first controller that generates the first control signal based on an error between the output current detected by the current sensor and a first threshold value; and a second controller that generates the second control signal based on an error between the output current detected by the current sensor and a second threshold value that is larger than the first threshold value, wherein the second controller comprises: a comparing unit that compares the output current detected by the current sensor with the second threshold value; and a control signal generating unit that generates the second control signal to cause the insulated converter to operate with a constant voltage conversion ratio when the output current detected by the current sensor is smaller than or equal to the second threshold value, and generates the second control signal to limit the output current of the insulated converter when the output current detected by the current sensor is larger than the second threshold value.