Voltage regulator protected against short -circuits

A voltage regulator device comprising:

• an output terminal of the voltage regulator having an output voltage coupled to a load;
• a voltage detection device supplying a detection signal having a first condition when a reference voltage is above the output voltage and a second condition when the reference voltage is below the output voltage;
• a first current limiting device supplying a first current to the load when the detection signal is in the first condition;
• a second current limiting device supplying a second current to the load when the detection signal is in the second condition.

A voltage regulator device comprising:

• an output terminal of the voltage regulator;
• an operational amplifier coupled between a first supply voltage and a second supply voltage having a noninverting input terminal, an inverting input terminal coupled to a reference voltage, and an output terminal;
• an output transistor having a gate, source, and drain wherein the gate is coupled to the output terminal of the operational amplifier, the source is coupled to the first supply voltage, and the drain is coupled to the output terminal of the voltage regulator;
• a comparator having a first input terminal connected to a reference voltage, a second input terminal connected to the output terminal of the voltage regulator, and first and second output terminals;
• a switching circuit having a first and second control terminals coupled to the first and second output terminals of the comparator, a first signal terminal, a second signal terminal, and a current input terminal;
• a first control circuit having a first terminal coupled to the first signal terminal, a control terminal coupled to the first signal terminal, a first reference current coupled to the first signal terminal, and a second terminal coupled to a second supply voltage;
• a first switch having a control terminal coupled to the first signal terminal, a first terminal coupled to a second supply voltage, and a second terminal coupled to the control output terminal;
• a second control circuit having a first terminal coupled to the second signal terminal, a control terminal coupled to the second signal terminal, a second reference current coupled to the second signal terminal, and a second terminal coupled to a second supply voltage;
• a second switch having a control terminal coupled to the second signal terminal, a first terminal coupled to the second supply voltage, and a second terminal coupled to the control output terminal;
• a voltage level control circuit having a first resistor having a first and second terminals wherein the first terminal is coupled to the first supply voltage and the second terminal is coupled to the third terminals of the first and second switches, a first transistor having gate, source and drain terminals wherein the gate is coupled to the second terminal of the first resistor, the source is coupled to the first supply voltage, and the drain is coupled to the output terminal of the operational amplifier, and a second transistor having gate, source, and drain terminals wherein the gate terminal is coupled to the output terminal of the operational amplifier, the source terminal is coupled to the first supply voltage, and the drain terminal is coupled to the current input terminal of the switching circuit.

A method of controlling an output voltage comprising:

• determining whether the output voltage is above or below a reference voltage;
• outputting a first signal if the output voltage is above the reference voltage;
• selecting a first feedback loop if the first signal indicates the output voltage is above the reference voltage supplying a first feedback current to lower the output voltage when the first feedback loop is selected;
• and
• selecting a second feedback loop if the first signal indicates the output voltage is below the reference voltage supplying a second feedback current to lower the output voltage when the second feedback loop is selected.