The INA260 accepts two kinds of analog inputs: namely, a current through the internal shunt resistor and a voltage between the V_BUS pin and GND. Configure the INA240 in the GUI to digitize either one or both of these inputs in serial order. The high current lug connectors designated T1 and T2 are the terminations of the internal 2-mΩ shunt resistor, therefore connect T1 and T2 in series with the input current source and load (see Figure 2-1). The INA260 is a bidirectional device and thus current can flow through the shunt resistor in either direction.

The V_BUS input of the INA260 is accessible through pin 2 of header J1. Pins 1 and 3 of J1 are connected to IN+ and IN–, respectively. Note that the V_BUS input is independent of the current input (that is, the V_BUS input can be applied with or without a load), and the INA260 provides an accurate voltage reading. However, the device also passively multiplies the measured values of V_BUS and input current to generate a power value. For the power calculation to be meaningful, V_BUS must represent the voltage drop created by the input current across the load. Therefore, for accurate load power measurements, short the V_BUS pin to IN+ or IN– (on header J1) depending on the location of the load. For example, for the arrangement in Figure 2-1, short V_BUS to IN– for an accurate load power calculation.

The EVM PCB also includes placeholders for the TVS devices to protect the INA260 inputs from excessively high common-mode voltages. The pads for these uninstalled devices, D3 and D4, are located on the bottom side of the EVM PCB and are suitable for DO-214AB package.