Low power proportional to absolute temperature current and voltage generator
First Claim
Patent Images
1. A proportional to absolute temperature (PTAT) circuit, the circuit comprising:
- a first set of circuit components comprising a pair of bipolar transistors operating at different current densities to generate a base-emitter voltage difference as a first voltage component, a resistive load element coupled to an emitter of a bipolar transistor of the set of bipolar transistors, and a bias generator configured to generate a first bias voltage and provide a first bias current to the resistive load element; and
a second set of circuit components operably biased by the first bias voltage and providing a second bias current to the resistive load element of the first set of circuit components, wherein the second set of circuit components is configured to generate at least a second voltage component related to a base-emitter voltage difference.
4 Assignments
0 Petitions
Accused Products
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.
-
Citations
25 Claims
-
1. A proportional to absolute temperature (PTAT) circuit, the circuit comprising:
-
a first set of circuit components comprising a pair of bipolar transistors operating at different current densities to generate a base-emitter voltage difference as a first voltage component, a resistive load element coupled to an emitter of a bipolar transistor of the set of bipolar transistors, and a bias generator configured to generate a first bias voltage and provide a first bias current to the resistive load element; and a second set of circuit components operably biased by the first bias voltage and providing a second bias current to the resistive load element of the first set of circuit components, wherein the second set of circuit components is configured to generate at least a second voltage component related to a base-emitter voltage difference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. 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:
-
a plurality of circuit elements coupled to a single biasing current, a first set of current elements configured to operate as a bias voltage generator, a bias current generator as a first PTAT voltage cell of the circuit, wherein a PTAT voltage is generated at a common node within the first set of circuit elements; and a second set of circuit elements biased using the bias voltage generated from the first set of circuit elements and configured to return at least one bias current to the common node within the first set of circuit elements, wherein the second set of circuit elements includes a second PTAT cell of the PTAT circuit. - View Dependent Claims (15, 16, 17, 18, 19, 20)
-
-
21. A method of generating a proportional to absolute temperature (PTAT) voltage, the method comprising:
-
coupling a plurality of circuit elements to a single biasing current; configuring a first set of circuit elements to operate as a bias voltage generator, a bias current generator and as a first PTAT voltage cell of a circuit, wherein a PTAT voltage is generated at a common node within the first set of circuit elements; biasing a second set of circuit elements using the bias voltage generated from the first set of circuit elements, wherein the second set of circuit elements returns at least one bias current to the common node within the first set of circuit elements; configuring the second set of circuit elements to operate as a second PTAT cell of the circuit; and combining PTAT voltages from the first and second PTAT cells of the circuit at an output of the circuit to generate a PTAT voltage. - View Dependent Claims (22, 23, 24, 25)
-
Specification