DC—DC converter

A DC—DC converter comprising the following:

• a switching power supply unit, which has a switching element that can be turned on/off at high frequency and can turn on/off the aforementioned switching element to convert a DC input voltage into a DC output voltage;
• an error amplifier, which compares the aforementioned DC output voltage obtained from the aforementioned switching power supply unit with a reference value and outputs an error signal corresponding to the comparison error at a selected response speed, that is, either a first response speed or a second response speed higher than the first response speed;
• a switching control unit, which generates a switching drive pulse corresponding to the aforementioned error signal output from the error amplifier for making the DC output voltage consistent with the aforementioned reference value and sends the switching drive pulse to the aforementioned switching element;
• and
• a response speed selection circuit, which compares the aforementioned DC output voltage with a desired monitoring value and selects the aforementioned first response speed as the response speed of the aforementioned error amplifier when the DC output voltage is within the range of the aforementioned monitoring value and selects the second response speed as the response speed of the error amplifier when the DC output voltage is out of the range of the monitoring value.

A DC—DC converter comprising the following:

• a switching power supply unit, which has a switching element that can be turned on/off at high frequency and can turn on/off the aforementioned switching element to convert a DC input voltage into a DC output voltage;
• an error amplifier, which compares the aforementioned DC output voltage obtained from the aforementioned switching power supply unit with a reference value and outputs an error signal corresponding to the comparison error at a selected gain, that is, either a first gain or a second gain higher than the first gain;
• a switching control unit, which generates a switching drive pulse corresponding to the aforementioned error signal output from the error amplifier for making the DC output voltage consistent with the aforementioned reference value and sends the switching drive pulse to the aforementioned switching element;
• and
• a gain selection circuit, which compares the aforementioned DC output voltage with a desired monitoring value and selects the aforementioned first gain as the gain of the aforementioned error amplifier when the DC output voltage is within the range of the aforementioned monitoring value and selects the second gain as the gain of the error amplifier when the DC output voltage is out of the range of the monitoring value.

A DC—DC converter comprising the following:

• a switching power supply unit, which has a switching element that can be turned on/off at high frequency and can turn on/off the aforementioned switching element to convert a DC input voltage into a DC output voltage;
• an error amplifier, which compares the aforementioned DC output voltage obtained from the aforementioned switching power supply unit with a reference value and outputs an error signal corresponding to the comparison error using a selected bias current, that is, either a first bias current or a second bias current larger than the first bias current;
• a switching control unit, which generates a switching drive pulse corresponding to the aforementioned error signal output from the error amplifier for making the DC output voltage consistent with the aforementioned reference value and sends the switching drive pulse to the aforementioned switching element;
• and
• a bias current selection circuit, which compares the aforementioned DC output voltage with a desired monitoring value and selects the aforementioned first bias current as the bias current of the aforementioned error amplifier when the DC output voltage is within the range of the aforementioned monitoring value and selects the second bias current as the bias current of the error amplifier when the DC output voltage is out of the range of the monitoring value.

A DC—DC converter comprising the following:

• a switching power supply unit, which has a switching element that can be turned on/off at high frequency and can turn on/off the aforementioned switching element to convert a DC input voltage into a DC output voltage;
• an error amplifier, which has a differential amplifier, which compares the aforementioned DC output voltage obtained from the aforementioned switching power supply unit with a reference value and outputs an error signal corresponding to the comparison error, and an output circuit, which includes an output resistor and a capacitor connected in series between the output terminal of the aforementioned differential amplifier and ground potential, and which can select the resistance of the aforementioned output resistor between a first resistance and a second resistance higher than the first resistance;
• a switching control unit, which generates a switching drive pulse corresponding to the aforementioned error signal output from the error amplifier for making the DC output voltage consistent with the aforementioned reference value and sends the switching drive pulse to the aforementioned switching element;
• and
• an output resistance selection circuit, which compares the aforementioned DC output voltage with a desired monitoring value and selects the aforementioned first resistance as the resistance of the output resistor in the aforementioned error amplifier when the DC output voltage is within the range of the aforementioned monitoring value and selects the second resistance as the resistance of the output resistor when the DC output voltage is out of the range of the monitoring value.