The TPS53353EVM-744 contains a 10-Ω series
resistor in the feedback loop for loop response analysis.
- Set up EVM as described in Section 4 and Figure 4-2.
- Connect a isolation transformer to test points marked TP10
and TP11.
- Connect input signal amplitude measurement probe (channel
A) to TP10. Connect a output signal amplitude measurement probe (channel B)
to TP11.
- Connect ground lead of channel A and channel B to
TP12.
- Inject approximately 40 mV or less signal through the
isolation transformer.
- Sweep the frequency from 100 Hz to 1 MHz with a 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).