Patent ID: 6642699
Filing Date: 2003-11-04
Classification: G05F,Y10S

Abstract:
A bandgap voltage reference circuit comprising the following:a bandgap voltage source configured to generate a bandgap voltage during operation of the bandgap voltage reference circuit, the bandgap voltage having temperature dependencies; one or more differential pairs each comprising the following: a current source; a negative temperature shift voltage source that has a negative temperature shift; a positive temperature shift voltage source that has a positive temperature shift; a current line configured to carry an error current contribution from the differential pair during operation; a first transistor having a first terminal connected to the current source, having a second terminal connected to the current line, and having a control terminal that is connected to one of the negative temperature shift voltage source or the positive temperature shift voltage source, wherein the current passing from the first terminal to the second terminal is controlled by the voltage at the control terminal; and a second transistor having a first terminal connected to the current source, having a second terminal connected to a current sink, and having a control terminal that is connected to the other of the negative temperature shift voltage source or the positive temperature shift voltage source, wherein the current passing from the first terminal of the second transistor to the second terminal of the second transistor is controlled by the voltage at the control terminal of the second transistor, wherein the current line from each of the one or more differential pairs are connected together to form a summed current line that carries a total corrective current, wherein the summed current line is coupled, directly or indirectly, to the bandgap voltage source so as to at least partially compensate for the temperature dependencies present in the bandgap voltage.