Two terminal temperature transducer having circuitry which controls the entire operating current to be linearly proportional with temperature

A two terminal temperature transducer including circuitry which produces an output which is the entire operating current that varies linearly with temperature, said circuitry comprising:

• a differential input stage including first and second transistors having differing operational current densities;
• current supplying means for supplying current through said first and second transistors to operate said first and second transistors at different current densities and to produce a difference between the respective base-to-emitter voltages, said difference in base-to-emitter voltages corresponding to a first reference voltage which is proportional to absolute temperature;
• a third transistor having a base-to-emitter voltage corresponding to a second reference voltage which is complementary to absolute temperature, said third transistor being coupled to said differential input stage so that a portion of said base to emitter voltage of said third transistor equals said difference in base to emitter voltages of said first and second transistors at a predetermined temperature;
• converting means for converting the difference between said first reference voltage and said second reference voltage into said entire operating current which is provided to the two terminals as said output.

A method of controlling the entire operating current of a two terminal temperature transducer to be linearly proportional with temperature, said method comprising the steps of:

• producing a first reference voltage which is proportional to absolute temperature;
• producing a second reference voltage which is complementary to absolute temperature;
• generating a voltage drop corresponding to said entire operating current flowing through the two terminals;
• comparing said voltage drop to a temperature sensitive voltage corresponding to the difference between said first reference voltage and said second reference voltage;
• and
• adjusting said entire operating current so as to equilibrate said voltage drop and said temperature sensitive voltage.