Along with space saving benefits, the integration of the HV resistive divider also increases accuracy. Previous designs with external resistors have higher temperature and lifetime drifts; the elimination of external resistors eliminates a majority of the total error. More specifically, the temperature drifts of external resistors can drift apart, compounding over time. Ordinarily, external resistor dividers use HV resistors in the upper part of the divider and low voltage (LV) resistors in the lower part of the divider. These LV resistors are frequently of a different type, construction, or material. An integrated resistive divider uses the same material for both the upper and lower resistors, which results in a very low temperature coefficient. Any remaining error of the resistive divider is then calibrated out at production, practically eliminating the resistive divider error entirely. Consider the following example:

Figure 2-2 External Resistor Design

Figure 2-3 Integrated Resistor Design

External Resistor Worst Case Drift Error:

Integrated Resistor Worst Case Drift Error:

As the external resistors can shift in opposite directions, this amounts to over 2/3 of the total signal chain error; an additional 1%. This makes it challenging for external resistor designs to achieve <1% accuracy over temperature and lifetime unlike the HV integrated resistor products.