The TPS53219EVM-690 contains a 10-Ω series resistor in the feedback loop for loop response analysis.

1. Set up EVM as described in Section 4 and Figure 4-2.
2. Connect an isolation transformer to test points marked TP9 and TP10.
3. Connect a input signal amplitude measurement probe (channel A) to TP9. Connect output signal amplitude measurement probe (channel B) to TP10.
4. Connect ground lead of channel A and channel B to TP11.
5. Inject approximately 40-mV or less signal through the isolation transformer.
6. Sweep the frequency from 100 Hz to 1 MHz with 10 Hz or lower post filter. The control loop gain and phase margin can be measured.
7. Disconnect isolation transformer from bode plot test points before making other measurements (signal injection into feedback can interfere with accuracy of other measurements).