Understanding Dual Terminator Resistor Networks

One of the least understood resistor network schematics in the industry today is the dual-resistor terminator schematic. This ‘unique’ electrical schematic makes it impossible to measure the individual R1 and R2 values using a simple ohmmeter, a two-wire / four-wire (Kelvin) digital ohmmeter, or a resistance-scanning system without active-guarding capabilities. However, two methods are available for determination of the accuracy of the resistor within each network if an active-guard test system is not available. This application note will explore both of these methods.