Patent ID: 8330445
Filing Date: 2012-12-11
Classification: G05F

Abstract:
1. A circuit to generate a voltage proportional to absolute temperature (VPTAT), comprising: a group of X transistors, each of which includes a base and a current path between a collector and an emitter; a plurality of switches configured to selectively change how at least some of the X transistors are connected within the circuit; a first base-emitter voltage branch configured to provide a first amount of current to the current path of each transistor within the first base-emitter voltage branch to produce a first base-emitter voltage (VBE a second base-emitter voltage branch configured to provide a second amount of current to the current path of each transistor within the second base-emitter voltage branch to produce a second base-emitter voltage (VBE a first current preconditioning branch configured to provide a current substantially equal to the first amount of current to each transistor within the first current preconditioning branch; and a second current preconditioning branch configured to provide a current substantially equal to the second amount of current to each transistor within the second current preconditioning branch; wherein the VPTAT is produced based on the first base-emitter voltage (VBE wherein the transistors within the first and second preconditioning branches are not used to produce VBE wherein the switches are used to selectively change over time which of the X transistors are in the first base-emitter voltage branch, the second base-emitter voltage branch, the first current preconditioning branch, and the second current preconditioning branch.