Test Procedure
9
SNVU589 – December 2017
Copyright © 2017, Texas Instruments Incorporated
TPS53119EVM-690 User Guide
7
Test Procedure
7.1
Line/Load Regulation and Efficiency Measurement Procedure
1. Set up EVM as described in
and
2. Ensure that load is set to constant resistance mode and to sink 0 Adc.
3. Ensure that all jumper configuration settings per
.
4. Ensure that the jumper provided in the EVM shorts on J3 before V
IN
is applied.
5. Increase V
IN
from 0 V to 12 V. Using V1 to measure input voltage.
6. Remove the jumper on J3 to enable the controller.
7. Use V2 to measure V
OUT
voltage.
8. Vary Load from 0-25 Adc; V
OUT
must remain in load regulation.
9. Vary Vin from 8 V to 14 V, V
OUT
must remain in line regulation.
10. Put the jumper on J3 to disable the controller.
11. Decrease load to 0 A.
12. Decrease V
IN
to 0 V.
7.2
Control Loop Gain and Phase Measurement Procedure
TPS53119EVM-690 contains a 10-
Ω
series resistor in the feedback loop for loop response analysis.
1. Set up EVM as described in
and
2. Connect isolation transformer to test points marked TP9 and TP10.
3. Connect input signal amplitude measurement probe (channel A) to TP9. Connect output signal
amplitude measurement probe (channel B) to TP10.
4. Connect ground lead of channel A and channel B to TP11.
5. Inject approximately 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.)