Texas Instruments TPS56121, User Manual, Page: 11 / 28

8 Test Procedures
8.1 Start Up/Shut Down Procedure
1. Set up the EVM as described in Section 5.3 and Figure 5-1 .
2. Ensure LOAD is set to sink 0 A
DC
.
3. Ensure jumper J3 set per Section 6.1 .
4. Increase VIN from 0 V
DC
to 12 V
DC
. Using V1 to measure VIN voltage.
5. Open jumper J3 to enable the converter.
6. Use V2 to measure VOUT voltage, A1 to measure VIN voltage.
7. Vary LOAD from 0 A
DC
to 15 A
DC
, VOUT should remain in load regulation.
8. Vary VIN from 8 V to 14 V, VOUT should remain in line regulation.
9. Short jumper J3 to disable the converter.
10. Decrease VIN to 0 V.
11. Decrease LOAD to 0 A.
8.2 Output Ripple Voltage Measurement Procedure
1. Follow Section 8.1 to set VIN and LOAD to desired operating condition.
2. Set oscilloscope for Output Voltage Ripple Measurement in Section 5.1.4 .
3. Connect oscilloscope probe with exposed metal barrel to TP3 and TP4 per Figure 8-1 . Using a leaded
ground connection may induce additional noise due to the large ground loop.
4. Follow Section 8.1 to power down.
TP4 TP3
Metal Ground Barrel
Probe Tip
Tip and Barrel Vout ripple
measurement
Figure 8-1. Tip and Barrel Output Voltage Ripple Measurement
www.ti.com Test Procedures
SLVU445C – MARCH 2011 – REVISED AUGUST 2021
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TPS56121 Step-Down Converter Evaluation Module User's Guide 11
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