LOW POWER PROPORTIONAL TO ABSOLUTE TEMPERATURE CURRENT AND VOLTAGE GENERATOR
First Claim
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1. A proportional to absolute temperature (PTAT) circuit, the circuit comprising:
- a first set of circuit components comprising a first bipolar transistor operating at a first collector current density and a second bipolar transistor operating at a second, lower, collector current density, the first and second bipolar transistors configured to provide a first voltage component related to a base-emitter voltage difference, the first set of circuit components further comprising a resistive load element and configured to generate a first bias current of the circuit having a value related to a value of the resistive load element and the first voltage component; and
a second set of circuit components coupled to the first set of circuit components and operably biased by a voltage originating within the first set of circuit components and providing a second bias current into the first set of circuit components.
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Abstract
A proportional to absolute temperature (PTAT) circuit is provided. By judiciously combining circuit elements into two or more cell it is possible to effectively dump bias current into impedance resistive element of a first cell from other cells of the circuit. As a result the circuit as a whole can operate with smaller resistive elements and therefore occupy less area when implemented in silicon. It is also possible to reduce the supply current that is required for providing specific output currents or voltages.
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Citations
28 Claims
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1. A proportional to absolute temperature (PTAT) circuit, the circuit comprising:
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a first set of circuit components comprising a first bipolar transistor operating at a first collector current density and a second bipolar transistor operating at a second, lower, collector current density, the first and second bipolar transistors configured to provide a first voltage component related to a base-emitter voltage difference, the first set of circuit components further comprising a resistive load element and configured to generate a first bias current of the circuit having a value related to a value of the resistive load element and the first voltage component; and a second set of circuit components coupled to the first set of circuit components and operably biased by a voltage originating within the first set of circuit components and providing a second bias current into the first set of circuit components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A proportional to absolute temperature (PTAT) circuit configured to generate a voltage at an output node of the circuit that is temperature dependent, the circuit comprising:
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a plurality of circuit elements coupled to a single biasing current, a first set of circuit elements configured to operate as a bias current generator and as a first PTAT voltage cell of the circuit; and a second set of circuit elements biased from the first set of circuit elements and configured to return at least one bias current to a common node within the first set of circuit elements. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A method of generating a proportional to absolute temperature (PTAT) voltage, the method comprising:
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providing a plurality of circuit elements coupled to a single biasing current; configuring a first set of circuit elements to operate as a bias current generator and as a first PTAT voltage cell of the circuit; and providing a second set of circuit elements biased from the first set of circuit elements and configured to return at least one bias current to a common node within the first set of circuit elements. - View Dependent Claims (24, 25, 26, 27, 28)
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Specification