Digital temperature sensor and method of measuring temperature

A digital temperature sensor comprising:

• a current generation circuit configured to generate a proportional to absolute temperature (PTAT)current that is proportional to an operation temperature, generate a complementary to absolute temperature (CTAT)current that is inversely proportional to the operation temperature, and generate a reference current that is fixed regardless of the operation temperature;
• an oscillation circuit configured to generate a first clock signal having a first cyclic period based on the PTAT current, generate a second clock signal having a second cyclic period based on the CTAT current, and generate a reference clock signal having a reference cyclic period based on the reference current such that the first cyclic period is inversely proportional to the PTAT current, the second cyclic period is inversely proportional to the CTAT current, and the reference cyclic period is fixed regardless of the operation temperature;
• a conversion circuit configured to generate a first temperature code and a second temperature code based on the first clock signal, the second clock signal and the reference clock signal such that the first temperature code decreases as the operation temperature increases and the second temperature code increases as the operation temperature increases;
• and
• a calculation circuit configured to calculate a difference between the first temperature code and the second temperature code and generate a corrected temperature code based on the difference, such that the corrected temperature code decreases as the operation temperature decreases.

A method comprising:

• generating a proportional to absolute temperature (PTAT)current that is proportional to an operation temperature;
• generating a complementary to absolute temperature (CTAT)current that is inversely proportional to the operation temperature;
• generating a first clock signal having a first cyclic period based on the PTAT current such that the first cyclic period is inversely proportional to the PTAT current;
• generating a second clock signal having a second cyclic period based on the CTAT current such that the second cyclic period is inversely proportional to the CTAT current;
• generating a first temperature code based on the first clock signal such that the first temperature code decreases as the operation temperature increases;
• generating a second temperature code based on the second clock signal such that the second temperature code increases as the operation temperature increases;
• calculating a difference between the first temperature code and the second temperature code;
• and
• generating a corrected temperature code based on the difference.