Techniques for sensing temperature and automatic calibration on integrated circuits
First Claim
1. An integrated circuit comprising a temperature sensing circuit, wherein the temperature sensing circuit comprises:
- a diode;
a comparator coupled to receive a signal from the diode;
a logic circuit coupled to receive an output of the comparator, the logic circuit generating a plurality of digital output signals; and
a first transistor network comprising a first plurality of transistors that are coupled in parallel to receive the plurality of digital output signals from the logic circuit, and a first plurality of resistors, wherein each of the first plurality of resistors is coupled in series with one of the first plurality of transistors.
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Accused Products
Abstract
Techniques are provided for sensing the temperature of an integrated circuit (IC). A diode is provided on an IC. The voltage across the diode varies with the temperature of the IC. A feedback loop is coupled around the diode to monitor the voltage across the diode. The feedback loop contains a comparator and logic circuitry that outputs a digital code. The digital code varies in response to changes in the diode voltage. The value of the digital code can be used to determine the temperature on the IC. Techniques are also provided for automatically calibrating a temperature sensing circuit to compensate for inaccuracies caused by variations in process, temperature, and supply voltage. A calibration circuit is added to the feedback loop in the temperature sensor. The calibration circuit generates an offset code that is used to adjust the digital code to compensate for variations in temperature, process, and supply voltage.
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Citations
20 Claims
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1. An integrated circuit comprising a temperature sensing circuit, wherein the temperature sensing circuit comprises:
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a diode; a comparator coupled to receive a signal from the diode; a logic circuit coupled to receive an output of the comparator, the logic circuit generating a plurality of digital output signals; and a first transistor network comprising a first plurality of transistors that are coupled in parallel to receive the plurality of digital output signals from the logic circuit, and a first plurality of resistors, wherein each of the first plurality of resistors is coupled in series with one of the first plurality of transistors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for sending temperature on an integrated circuit, the method comprising:
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comparing a voltage across a diode with a voltage from a first transistor network using a comparator, the first transistor network comprising first transistors coupled in parallel and first resistors coupled in series with the first transistors; converting an output of the comparator into a plurality of digital signals; and selectively enabling the first transistors in the first transistor network in response to the plurality of digital signals. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. An integrated circuit comprising:
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a comparator; an offset calibration circuit that generates a digital offset code in response to the output signal of the comparator; a first transistor network selectively enabling first transistors in response to the digital offset code; a logic circuit that generates second digital output signals in response to an output signal of the comparator; and a second transistor network selectively enabling second transistors in response to the second digital signals, wherein the comparator is coupled to receive a signal from the first and the second transistor networks, and states of second transistors in the second transistor network are held constant in response to a predefined digital code during an offset calibration mode. - View Dependent Claims (19, 20)
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Specification