The loop response of the TPS62175EVM-098 can be measured with two simple changes to the circuitry. First, install a 10-Ω resistor across the pads in the middle of the back of the PCB. The pads are spaced to allow installation of 0805- or 0603-sized resistors. Second, cut the short section of trace between the via on the VOS pin and the output capacitor C2. This change is shown in Figure 1-1. With these changes, an ac signal (10-mV, peak-to-peak amplitude recommended) can be injected into the control loop across the added resistor.

Figure 1-1 Loop Response Measurement Modification