TPS53819AEVM-123 contains a place holder for a 10-Ω series resistor in the feedback loop for loop response analysis.
- Replace R16 with a 10-Ω resistor.
- Set up EVM as described in Section 4 and Figure 4-3.
- Connect isolation transformer to test points marked TP13 and TP11.
- Connect input signal amplitude measurement probe (Loop B) to TP11. Connect output signal amplitude measurement probe (Loop A) to TP13.
- Connect ground lead of Loop A and Loop B to TP12.
- Inject around 10 mV or less signal through the isolation transformer.
- 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.
- Disconnect isolation transformer from bode plot
test points before making other measurements (Signal injection into feedback can
interfere with accuracy of other measurements).