Reference voltage generators, integrated circuits, and methods for operating the reference voltage generators

An integrated circuit comprising:

• a voltage regulator;
• and
• a reference voltage generator connected with the voltage regulator, the reference voltage generator comprising:
• a proportional to absolute temperature (PTAT) current source, the PTAT current source being capable of providing a first current that is proportional to a temperature;
• a current mirror comprising a first transistor and a second transistor, the current minor configured to generate a second current proportional to the first current, wherein a ratio of the first current to the second current is equal to a ratio of a gate width of the first transistor to a gate width of the second transistor;
• a voltage divider, the voltage divider being capable of receiving the second current, the voltage divider capable of outputting a reference voltage, the reference voltage being substantially independent from a change of the temperature, wherein the voltage divider comprises a third transistor and a fourth transistor, wherein the reference voltage is capable of being adjusted based on width/length ratios of the third and fourth transistors, and a gate of the third transistor is connected to a gate of the fourth transistor;
• and
• a transistor having a gate connected to the PTAT current source and a first terminal connected to the current mirror.

A method of generating a reference voltage, the method comprising:

• generating a first current using a proportional to absolute temperature (PTAT) current source, the first current being proportional to a temperature;
• generating a second current proportional to the first current using a current mirror, the current mirror comprising a first transistor and a second transistor, wherein a ratio of a gate width of the first transistor and a gate width of the second transistor is equal to a ratio of the first current to the second current;
• generating a third current using the PTAT current source, wherein the third current is proportional to the first current;
• and generating the reference voltage based on the second current using a voltage divider, wherein the voltage divider comprises a pair of diode-connected transistors, wherein generating the reference voltage comprises:
• passing the second current through a third transistor and a fourth transistor;
• and selecting a width/length ratio of the third and fourth transistors.