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|  | Anonymous
on 06/25 at 11:14 PM
| Category(s): | Technical Questions |
| Subject: | Problem with LM3743 |
| Message: (Notified via email on every direct response) |
Hi,
My name is Vladimir Ssorin and I have some issues with the implementation of LM3743MM voltage controller. We have used this DC-DC converter in PCB design as a power supply for FPGA (converting 5 V to 1.0 V).
The first test board with LM3743MM was assembled with FPGA, and we had no problem with this board (the voltage regulator was worked okay).
When we assembled the second board the power supply with LM3743MM didn?t work correctly (the output power was 0.9V). So next we were starting comparison these two boards. After some action the regulator on the first board has failed and now the board #1 works similar to the board #2. So we have two assembled boards with FPGA where the 1V power supplies don?t work.
Next we assembled test board with only this voltage regulator. We have measured different parameters of this board with and without load. The schematic and Bill of Material (BOM) of voltage regulator circuit are presented in attached file LM3743MM.pdf.
I have measured some parameters of this circuit. The measured results are presented in attached file LM3743MM.pdf. I have measured output voltage at the left side of the inductor, checked ILIM resistor, input and output voltages, waveforms of the gates and current supply of the board. These measurements were done for regulator without load and with different loads (3.3KOhm, 1KOhm, 500Ohm, 100Ohm, 50Ohm, 22Ohm and 2Ohm). Note that waveforms are not stable so I have attached a number of waveform snapshots.
Please suggest solutions that can resolve this issue!
Thanks in advance,
Vladimir Ssorin
Attached File - LM3743MM.pdf
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