Texas Instruments TPS51113, Руководство пользователя

Страница: 6 / 17

8 Test Procedure
8.1 Line/Load Regulation and Efficiency Measurement Procedure
1. Ensure that the load is set to constant resistance mode and to sink 0 A
DC
.
2. Ensure that the jumper provided in the EVM shorts on JP1 before V
IN
is applied.
3. Increase V
IN
from 0 V to 12 V, using V1 to measure input voltage.
4. Remove the jumper on JP1 to enable the controller.
5. Vary load from between 0 A
DC
and 25 A
DC
. V
OUT
should be remain in load regulation.
6. Vary V
IN
from 8 V to 14 V. V
OUT
should remain in line regulation.
7. Put the jumper on JP1 to disable the controller.
8. Decrease the load to 0 A.
9. Decrease V
IN
to 0 V.
8.2 Control Loop Gain and Phase Measurement Procedure
The TPS51113-EVM contains a 20-Ω series resistor in the feedback loop for loop response analysis.
1. Set up the EVM as described in Section 8.1 and Figure 7-2 .
2. Connect the isolation transformer to test points marked TP4 and TP3.
3. Connect an input signal amplitude measurement probe (channel A) to TP4.
4. Connect an output signal amplitude measurement probe (channel B) to TP3. Connect the ground lead of
channel A and channel B to TP9 and TP10.
5. Inject around 40-mV or less signal through the isolation transformer.
6. Sweep the frequency from 100 Hz to 1 MHz with a 10-Hz or lower post filter. The control loop gain and
phase margin can be measured.
7. Disconnect the isolation transformer from the bode plot test points before making other measurements
(Signal injection into feedback may interfere with accuracy of other measurements).
8.3 Test Points
Table 8-1. Test Point Functions
TEST POINTS NAME DESCRIPTION
TP1 V
IN
+ 12-V input
TP2 GND PGND for V
IN
TP3 CHB Input B for loop injection
TP4 CHA Input A for loop injection
TP5 SW Monitor switch node voltage
TP6 V
OUT
V
OUT
TP7 COMP Enable/COMP
TP8 GND PGND for V
OUT
TP9 GND GND for loop measurement
TP10 PGND PGND
TP11 PGOOD Power Good
8.4 Equipment Shutown Procedure
1. Shut down the load.
2. Shut down V
IN
.
3. Shut down the fan.
Test Procedure www.ti.com
6 TPS51113 Buck Controller Evaluation Module User's Guide SLUU359A – APRIL 2009 – REVISED FEBRUARY 2022
Submit Document Feedback
Copyright © 2022 Texas Instruments Incorporated