초록 ▼

A temperature set point circuit employs a pair of bipolar transistors operated at unequal current densities, with the difference between the transistors' base-emitter voltages appearing across a trim resistor connecting their emitters. A pair of trim resistors, one of which may be external to an int

A temperature set point circuit employs a pair of bipolar transistors operated at unequal current densities, with the difference between the transistors' base-emitter voltages appearing across a trim resistor connecting their emitters. A pair of trim resistors, one of which may be external to an integrated circuit embodiment of the set point circuit, forms a resistor divider with the inter-base resistor and are selected to produce a desired temperature trip-point.

대표청구항 ▼

[ I claim:] [1.] A resistor programmable set point temperature circuit for indicating whether the temperature of a circuit meets or exceeds a set point temperature, comprising:first and second supply voltage terminals,first and second bipolar transistors of like polarity, said second transistor havi

[ I claim:] [1.] A resistor programmable set point temperature circuit for indicating whether the temperature of a circuit meets or exceeds a set point temperature, comprising:first and second supply voltage terminals,first and second bipolar transistors of like polarity, said second transistor having an emitter area N times that of the first transistor, the emitters of both transistors coupled to a common terminal,first and second current sources connected to provide predetermined currents I1 and I2, respectively, to the collectors of said transistors,a resistor divider coupled between said first and second supply voltage terminals, a first resistor of said divider connected between the bases of said first and second transistors such that the difference in base-emitter voltages of said first and second transistors appears across said resistor, andan output stage connected to receive current from said second current source.