Integrated circuit interface with preset temperature dependence - uses four transistors to provide temp. independent output current proportional to control voltage, and temp. dependent current

摘要

The circuit consists of four identical transistors. The base of the first is connected to the emitter of the second. The base of the second and third transistor are connected together and the emitter of the third is connected to the base of the fourth. A control signal is applied as a voltage to a resistor connected to the collector of the first transistor and the output taken from the collector of the fourth transistor. A constanct current is passed through the second transistor with a positive temperature coefficient and through the third transistor from a current mirror controlled by an internal voltage reference and a resistance. The current in the second transistor is dependent only on absolute temperature and the resistance. The circuit may be used as an interface to produce a control output which is independent of temperature from an input which exhibits temperature dependence.