1. Field of the Invention
The present invention relates to voltage or current sources which generate a reference voltage or current as a predetermined function of temperature, and which can offset changes in a supply voltage.
2. Description of Related Art
Controlled voltage and current sources have a wide variety of applications in integrated circuit technology, and in other technologies. A variety of circuit design techniques have been developed for the purpose of generating a reference voltage which is stable with changes in temperature, or a reference voltage which does not change with fluctuations in the supply voltage. These circuits are relatively complex which require significant area on integrated circuits which implement them.
It is desirable to design a reference voltage or current source which uses a small number of transistors and can be adapted to provide a constant reference independent of temperature, or a reference which rises or falls with temperature in a predetermined relationship. Also, it is desirable to have such a reference source which is capable of offsetting any changes in the source voltage driving the circuit.