Texas Instruments TPS40131 Evaluation Module TPS40131EVM TPS40131EVM Datenbogen
Produktcode
TPS40131EVM
www.ti.com
5.3
Start Up and Test Procedure
5.4
Control Loop Gain and Phase Measurement Procedure
7. The control loop gain can be measured by
20
LOG
ǒ
ChannelB
ChannelA
ChannelA
Ǔ
.
Test Set Up
Figure 3. Output Ripple Measurement
1. Ensure LOAD is set to constant current mode and to sink 0A DC.
2. Set V
2. Set V
IN2
to 5V.
3. Increase V
IN1
from 0V to 12V, V
OUT
should be in regulation per
4. Vary LOAD from 0–40Adc, V
OUT
should remain in regulation per
for all combinations of load on
LOAD up to 40A.
5. Vary V
IN1
from 10.8V to 13.2V, V
OUT
should remain in regulation per
for all combinations of
load on LOAD up to 40A.
1. Connect 1 kHz–1MHz isolation transformer to test points marked TP5 and TP6.
2. Connect input signal amplitude measurement probe (channel A) to TP6.
3. Connect output signal amplitude measurement probe (channel B) to TP5.
4. Connect ground lead of channel A and channel B to TP11.
5. Inject 25mV or less signal through the isolation transformer.
6. Sweep the frequency from 100Hz to 1MHz with 10Hz or lower post filter.
2. Connect input signal amplitude measurement probe (channel A) to TP6.
3. Connect output signal amplitude measurement probe (channel B) to TP5.
4. Connect ground lead of channel A and channel B to TP11.
5. Inject 25mV or less signal through the isolation transformer.
6. Sweep the frequency from 100Hz to 1MHz with 10Hz or lower post filter.
8. Control loop phase is measured by the phase difference between Channel A an Channel B.
9. Disconnect isolation transformer from the bode plot test points before making other measurements
9. Disconnect isolation transformer from the bode plot test points before making other measurements
(Signal Injection into Feedback may interfere with accuracy of other measurements).
8
Using the TPS40131EVM, A 40A Single Output
SLVU198A – February 2007 – Revised May 2007
Two-Phase Synchronous Buck Converter