10.2.1 Design Requirements

In ATE and Motor Control applications, typically the systems are designed modular wherein the control module is located spatially away from the Device Under Test (DUT) module. Such a scheme allows ground potentials across modules to vary due to the impedance of the interconnects. This ground potential variation, in turn introduces inaccuracies to the DAC output when measured with respect to the remote or DUT ground. Figure 67 provides a method to compensate the variations in the remote ground. The ground variation in such applications is typically within ±300 mV that includes DC and 50 Hz/60 Hz mains frequency components. While the best way to handle this variation is to put opamps in level shifter configuration at each output, a low cost and low footprint solution is always preferable. The following sections focus on the latter approach.