Environ-stabilized voltage references

Abstract

<p>A new design approach for high performance voltage references has been developed. This approach exploits the inflection point property of a first-order voltage reference where the temperature derivative is zero at a temperature in the range of interest. By creating an ordered family of these references with the corresponding inflection points distributed across a wide temperature range and using a temperature trigger to continuously transition between these references, a highly accurate wide temperature range voltage reference is realizable. The resultant voltage references that have an output voltage that has been stabilized to temperature changes in the environment are termed "environ-stabilized" voltage reference. The implementation of an environ-stabilized voltage reference using this approach is verified through both transistor level and behavioral simulations. The implementation of a 3-family reference predicts an error voltage of less than 180[mu]V for a temperature between - 400C and 1000C. This is equivalent to a temperature coefficient of 1.06ppm/0C. Further reductions in the equivalent temperature coefficient are possible if the number of members in the family is increased. The performance degradation of the environ-stabilized voltage references due to process variations was also studied. A self-calibration scheme has been introduced to correct errors introduced by process variations. The result suggests the environ-stabilized reference approach can be used for the realization of highly accurate voltage references that operate over a wide temperature range throughout a wide range of the process variations.</p>