Texas Instruments TPS546B24AEVM-2PH, User Manual, Page: 16 / 47

6.3 Control Loop Gain and Phase Measurement Procedure
The TPS546B24AEVM-2PH includes a 49.9-Ω series resistor in the feedback loop for V
OUT
. The resistor is
accessible at the test points TP17 and TP18 for loop response analysis. These test points should be used during
loop response measurements as the perturbation injecting points for the loop. See the description in
Table 6-3 .
Table 6-3. List of Test Points for Loop Response Measurements
Test Point Node Name Description Comment
TP18 CH_B Input to feedback divider of V
OUT
The amplitude of the perturbation at this node should be limited to less than 30 mV.
TP17 CH_A Resulting output of V
OUT
Bode can be measured by a network analyzer with a CH_B/CH_A configuration.
Measure the loop response with the following procedure:
1. Set up the EVM as described in Section 4.2 .
2. For V
OUT
, connect the isolation transformer of the network analyzer from TP18 to TP17.
3. Connect the input signal measurement probe to TP18. Connect the output signal measurement probe to
TP17.
4. Connect the ground leads of both probe channels to TP20.
5. On the network analyzer, measure the Bode as TP18/TP17 (In/Out).
Test Procedure www.ti.com
16 TPS546B24A 2-Phase SWIFT™ Step-Down Converter Evaluation Module
User's Guide SLUUC48A – FEBRUARY 2020 – REVISED FEBRUARY 2022
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