Texas Instruments TPS53317AEVM-726, User Manual, Page: 12 / 30

Test Procedure
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7.2 Control Loop Gain and Phase Measurement Procedure
TPS53317AEVM-726 contains a 10- Ω series resistor in the feedback loop for loop response analysis.
1. Set up EVM as described in Figure 3 .
2. Connect isolation transformer to test points marked TP12 and TP13.
3. Connect input signal amplitude measurement probe (channel A) to TP12. Connect output signal
amplitude measurement probe (channel B) to TP13.
4. Connect ground lead of channel A and channel B to TP14.
5. Inject around 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 may interfere with accuracy of other measurements).
7.3 List of Test Points
Table 6. The Functions of Each Test Points
Test Points Name Description
TP1 VIN Input voltage
TP2 PGND PGND for VIN
5-V power supply for analog circuits and
TP3 V5IN
gate drive
TP4 PGND PGND for V5IN
TP5 VOUT Output voltage
TP6 PGND PGND for VOUT
TP7 PGOOD Power good
TP8 EN Enable pin
TP9 SW Switching node
TP10 AGND Signal ground
TP11 VREF Internal 2-V reference voltage output
TP12 CHA Input A for loop injection
TP13 CHB Input B for loop injection
TP14 AGND Signal ground
TP15 REFIN Target output voltage input
7.4 Equipment Shutdown
1. Shut down VIN
2. Shut down V5IN
3. Shut down Load
4. Shut down FAN
12 TPS53317AEVM-726 D-CAP+™ Mode Synchronous Step-Down Integrated SLUUBD2 – November 2015
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