While several parameters are important in the selection of voltage references, the two that stand out as potentially contributing the greatest errors are initial accuracy and temperature coefficient (TC). Noise, thermal hysteresis, line and load regulation and long term stability are also not be neglected when making a selection, but their contributions to error are shadowed by initial accuracy and TC. This paper discusses how an average precision voltage reference can be configured to achieve <1ppm/°C performance with an initial accuracy of better than 0.01%.