Circuit for providing a current proportional to absolute temperature
AssigneeHarris Corporation
InventorOtto H. Schade, Jr.
Life of this patent
Estimating the term…
Abstract
An integrated circuit for providing a current proportional to absolute temperature comprises circuitry for providing a first current exhibiting substantially zero temperature coefficient; circuitry for providing a second current exhibiting a negative temperature coefficient; and circuitry for summing the first and second currents for providing a third current proportional to absolute temperature.
Claims16
An integrated circuit for providing a current proportional to absolute temperature, comprising:
- current mirror means for producing a reference current;
- a first circuit means coupled between said current mirror means and a summing node for providing thereto a first current exhibiting substantially zero temperature coefficient;
- second circuit means coupled between said current mirror means and said summing node for providing thereto a second current exhibiting a negative temperature coefficient;
- and
- output means coupled to said summing node for summing said first and second currents for providing and carrying a third current through said output means exhibiting a positive temperature coefficient.
An integrated circuit for providing a current proportional to absolute temperature, comprising:
- a current summing node for providing an output current to a load;
- a transistor having emitter, base, and collector electrodes, said collector electrode being connected to said summing node for providing a first current thereat;
- a resistor, exhibiting a positive temperature coefficient of resistance, having a first end connected to said emitter electrode and having a second end;
- current mirror means for producing a reference current and also having a node at which is produced a voltage exhibiting a negative temperature coefficient;
- means coupled to said node for applying between said second end of said resistor and said base electrode said voltage exhibiting a negative temperature coefficient for causing said first current to exhibit a negative temperature coefficient;
- and circuit means, coupled to said current mirror means, having an output connected to said summing node for providing thereat a second current, responsive to said reference current, of opposite polarity sense to, and of magnitude greater than, said first current, said second current exhibiting a small temperature coefficient in comparison with said negative temperature coefficient such that said output current exhibits a positive temperature coefficient.
An integrated circuit for providing a current proportional to absolute temperature, comprising:
- a feedback loop of first and second current mirror amplifiers of opposite polarity types being interconnected with an output of each current mirror amplifier being connected to the input of the other so as to exhibit a loop gain, at least one of said current mirrors including resistive means for providing resistive emitter degeneration in an output transistor thereof so as to exhibit a current gain diminishing with current increase, said loop gain exceeding unity at a first, smaller current and dropping to unity at a second, greater current for stable operation thereat such that said second current is substantially independent of temperature;
- mirroring means coupled between one of said current mirror amplifiers and a summing node for providing thereto a third current proportional to said second current;
- means coupled between one of said current mirror amplifiers and said summing node for providing thereto a fourth current exhibiting a negative temperature coefficient;
- and
- summing output means coupled to said summing node for providing an output current through said output means equal to the difference between said third and fourth currents.
Dependencies are inferred from the claim text.