Characteristics of burden resistors for high-precision DC current transducers

The DC current transducer (DCCT) and accompanying A/D converter determine the precision of a power converter in accelerator operation. In the LHC context this precision approaches 10^-6 (1 ppm). Inside the DCCT a burden resistor is used to convert the current to an output voltage. The performance of this resistor is crucial for the accuracy, temperature behaviour, settling time and long- term drift of the DCCT. This paper reports on evaluations, a new parameter called "power coefficient" (PC) and test results from some different types of resistors available on the market.