Low power voltage generator circuit

A voltage generation method comprising:

• generating current through a first resistor to have a first signed temperature coefficient based on a difference in current density between transistors in a circuit loop;
• and
• generating a voltage of a transistor coupled to an output transistor through a second resistor with the transistor being a field effect transistor (FET) sized such that the voltage has a second signed temperature coefficient, opposite in sign to the first signed temperature coefficient, wherein the transistors of the circuit loop, the output transistor, the transistor coupled to the output transistor, the first resistor, and the second resistor are sized to provide an output voltage at an output node having a substantially flat temperature coefficient;
• and
• decoupling temperature coefficient trimming from absolute voltage trimming at the output node using a trimming circuit coupled to the output transistor, the transistor coupled to the output transistor, and a second transistor;
• wherein the second transistor is coupled to the transistor coupled to the output transistor and has a different threshold voltage than the transistor coupled to the output transistor.

A voltage generator circuit comprising:

• a circuit loop for generating current through a first resistor to have a first signed temperature coefficient based on a difference in current density between transistors in the circuit loop;
• and
• means for generating a voltage of a transistor coupled to an output transistor through a second resistor with the transistor being a field effect transistor sized such that the voltage has a second signed temperature coefficient, opposite in sign to the first signed temperature coefficient, wherein the transistors of the circuit loop, the output transistor, the transistor coupled to the output transistor, the first resistor, and the second resistor are sized to provide an output voltage at an output node having a substantially flat temperature coefficient;
• and
• trimming means for decoupling temperature coefficient trimming from absolute voltage trimming at the output node, wherein the trimming means includes a second transistor having a control terminal coupled to a control terminal of the transistor coupled to the output transistor and having a threshold voltage different than a threshold voltage of the transistor coupled to the output transistor.