Given the tight tolerance required by FPGAs, it is not enough to look at just the nominal voltage output level of a voltage regulator. It is important to assess the entire range and tolerance of the FPGA and ensure that the power management device can match the requirements. For example, if an FPGA has a nominal constant current voltage of 1.2V and a 5% tolerance, the total range is from 1.14 to 1.26V. Many regulators have a 1.25V nominal minimum output which, by itself, is within the tolerance range of the FPGA. However, factoring in a typical voltage regulator accuracy of 3% results in a possible voltage of 1.287V. Clearly, the voltage range exceeds the FPGA’s upper end tolerance of 1.26V and could possibly damage the device. So, carefully scrutinize a regulator’s nominal value and tolerance. These requirements must also be maintained over line and load transients as well as the full temperature range.