Texas Instruments SWIFT TPS548A20, Руководство пользователя

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7 Test Procedure
7.1 Line and Load Regulation and Efficiency Measurement Procedure
1. Set up the EVM as described in Section 5 and Figure 5-2 .
2. Ensure the load is set to constant-resistance mode and to sink at 0 ADC.
3. Ensure all jumper setting are configured as shown in
Section 6 .
4. Ensure the jumper provided in the EVM shorts on J2 before VIN is applied.
5. Increase VIN from 0 to 12 V. Use V1 to measure input voltage.
6. Remove the jumper on J2 to enable the controller.
7. Use V2 to measure the VOUT voltage.
8. Vary the load from 0 to 10 ADC, VOUT must remain in load regulation.
9. Vary VIN from 8 to 14 V, VOUT must remain in line regulation.
10. To disable the converter, place the jumper on J2.
11. Decrease the load to 0 A
12. Decrease VIN to 0 V.
7.2 Control-Loop Gain and Phase-Measurement Procedure
The TPS548A20EVM-737 contains a 10-Ω series resistor in the feedback loop for loop response analysis.
1. Set up the EVM as described in
Section 5 and Figure 5-2 .
2. Connect the isolation transformer to the test points marked TP5 and TP8.
3. Connect the input-signal amplitude-measurement probe (channel A) to TP10. Connect the output-signal
amplitude-measurement probe (channel B) to TP11.
4. Connect the ground lead of channel A and channel B to TP15.
5. Inject around 20 mV or less signal through the isolation transformer.
6. To measure control-loop gain and phase margin, change the frequency from 100 Hz to 1 MHz using a 10-Hz
or less post filter.
7. Disconnect the isolation transformer from the bode-plot test points before making other measurements.
• Signal injection into feedback can interfere with the accuracy of other measurements.
www.ti.com Test Procedure
SLUUBC0A – DECEMBER 2015 – REVISED AUGUST 2021
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TPS548A20 SWIFT™ Step-Down Converter Evaluation Module User's Guide 11
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