Texas Instruments TPS51200 Sink Source DDR Termination Regulator TPS51200EVM TPS51200EVM Datenbogen
Produktcode
TPS51200EVM
5.5
Loop Measurement (TP10, TP11 and TP14)
5.5.1
Control Loop Measurement Process
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Test Procedure
TPS51200EVM contains a 10-
Ω
series resistor in the feedback loop. The control loop measurement set up
as shown in
.
Figure 4. Control Loop Measurement Setup
1. Set up EVM as shown in
2. Follow test procedure at Step 1 through Step 9 of 5.1.1(DDR), 5.2.1 (DDR2), 5.3.1 (DDR3) or 5.4.1 (LP
DDR3) to select the desired application and load condition.
3. Connect Input Signal Amplitude Measurement Probe (Channel A) to TP11.
4. Connect Output Signal Amplitude Measurement Probe (Channel B) to TP10.
5. Connect Ground Lead of Channel A and Channel B to TP14.
6. Inject approximately 100 mV or less signal through an isolation transformer.
7. Sweep frequency from 1 kHz to 10 MHz with a 10-Hz or lower post filter.
8. Measure the control loop gain margin and phase margin. (Refer to Bode plot
4. Connect Output Signal Amplitude Measurement Probe (Channel B) to TP10.
5. Connect Ground Lead of Channel A and Channel B to TP14.
6. Inject approximately 100 mV or less signal through an isolation transformer.
7. Sweep frequency from 1 kHz to 10 MHz with a 10-Hz or lower post filter.
8. Measure the control loop gain margin and phase margin. (Refer to Bode plot
in Section 6.)
9. Disconnect isolation transformer, probe Channel A and Channel B before making other measurements.
10. Decrease Load 1 to 0 A.
11. Decrease Load 2 to 0 mA.
12. Set switch S1 to the OFF position.
13. Decrease DC Source 3 to 0 V.
14. Decrease DC Source 2 to 0 V.
15. Decrease DC Source 1 to 0 V.
10. Decrease Load 1 to 0 A.
11. Decrease Load 2 to 0 mA.
12. Set switch S1 to the OFF position.
13. Decrease DC Source 3 to 0 V.
14. Decrease DC Source 2 to 0 V.
15. Decrease DC Source 1 to 0 V.
SLUU323 – JUNE 2008
Using theTPS51200 EVM Sink/Source DDR Termination Regulator
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