Patent ID: 6957910

Claim:
A circuit in an integrated circuit for measuring temperature dependent voltages of a temperature sensing element incorporated in the integrated circuit, the circuit comprising: a voltage generator circuit comprising: a first current source providing a first current; a second current source providing a second current, the first current and the second current having a fixed ratio; a temperature sensing element; a first current switch coupling the second current source to the temperature sensing element; a second current switch coupling the first current source to the temperature sensing element, wherein the first current switch and the second current switch are alternately asserted to alternately apply the first current and the second current to the temperature sensing element to generate the temperature dependent voltages; a first sampling switch coupling the voltage at the temperature sensing element to a first node, the first sampling switch comprising a self-bootstrapping constant on-resistance boosted switch circuit incorporating a pedestal voltage compensation circuit; and a second sampling switch coupling the voltage at the temperature sensing element to a second node, the second sampling switch comprising a self-bootstrapping constant on-resistance boosted switch circuit incorporating a pedestal voltage compensation circuit, wherein the first sampling switch samples the temperature dependent voltage of the temperature sensing element when the temperature sensing element is being excited by the second current and provides a first voltage indicative of the sampled voltage at the first node, and the second sampling switch samples the temperature dependent voltage of the temperature sensing element when the temperature sensing element is being excited by the first current and provides a second voltage indicative of the sampled voltage at the second node, whereby a difference between the first voltage and the second voltage is used to determine the temperature of the integrated circuit.