Patent ID: 8228052

Claim:
A proportional to absolute temperature (PTAT) voltage circuit configured to provide a voltage reference at an output thereof, the circuit comprising: a first set of circuit elements, the first set of circuit elements arranged to provide a complementary to absolute temperature (CTAT) voltage or current; and a second set of circuit elements, the second set of circuit elements arranged to provide a proportional to absolute (PTAT) voltage or current, wherein: the second set of circuit elements includes at least one bipolar transistor and an active element being resistorless, the active element having a resistance, the first set of circuit elements includes at least one bipolar transistor operated at n times a current density of the at least one bipolar transistor of the second set of circuit elements, a first terminal of the active element is connected to a terminal of the at least one bipolar transistor of the first set of circuit elements, a second terminal of the active element is connected to a terminal of the at least one bipolar transistor of the second set of circuit elements, and the active element of the second set of circuit element limits a collector voltage of the at least one bipolar transistor of the second set of circuit elements, thereby reducing an Early Voltage (VA) of the at least one bipolar transistor of the second set of circuit elements.