Hello John, I understand it now, I would require some more input from you in order to reproduce this failure in our labs. How many units have you tested and what percentage of those units were faulty? Does this issue is board dependent or can you reproduce the same issue when the controller is run open loop? This excess current happens at -40degC: can you also share the line and load condition during this issue? Regards, Sonal
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Forum post: RE: UCC1804: UCC1804J IC damaged and pulling excessive current at start up prior to reaching UVLO start up
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Forum post: RE: TPS23881EVM-008: TPS23881 EVB POE Auto pin setting issue
Hi Caspar, You test results are expected. Please me explain the reason one by one. 1.PSE set 45W/PD set class 5=>output about above 40W [Penny]The PD's DCDC has 90% efficiency. Considering cable losses and PSE's 2.5% PCUT accuracy, ~40W is a reasonable number. 2.PSE set 45W/PD set class 6=>output about under 30W [Penny]This is expected due to power demotion 3.PSE set 45W/PD set class 7=>output about under 30W 4.PSE set 45W/PD set class 8=>output about under 30W [Penny]These 2 are also expected. The "class 5" in your highlighted box is a typo. These should be class 4. We are working with documentation team to fix this. Sorry for the confusion. Best regards, Penny
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Forum post: UCC28742: What is the recommended bias supply operating voltage?
Part Number: UCC28742 I am using UCC28742 to design flyback SMPS. The bias supply operating voltage range is 9 to 35V. But what is the recommended bias supply operating voltage ? It should be above UVLO turn threshold i.e. 21.6V or anything else ?
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Forum post: RE: LM5170EVM-BIDIR: Normal boost operation not working: Input and Output at same voltage level
Hi, Yes, R4=100kOhm is soldered. I think you meant J17-Pin 5. Even though I have connected a jumper wire, I am not using it. The circuit starts up without it, but both voltages are the same. J21 closed to Pin 1-2. I actually didn't run the buck mode, this was the first test and found the issue. I have one more EVM, I will try to do the same changes and test the bias. How can I test the other new EVM for just bias? Can I test it without any load? I don't have a programmable load. I have a programmable supply and a 48V,2kW motor (which can be load from 200W) I will try to supply 10V at J17 Pin43 and check if 3.3V and 5V are produced. If fails, I will replace U3 and U4 or remove and supply externally. Will try these changes and get back to you.
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Forum post: RE: TPS57160-Q1: Power sequencing requirements?
Orlando, thanks for the hint. yes we were suspecting the diode too.. but the input caps are fairly small totaling 7uF. The power supply was a linear supply not that fast when turning on. it was measured like 1ms to 30V. given I=C dv/dt it would be on the order of hundred mA. and this is a 1.5A part.. another question mark is on the boot strap. since there is no input voltage, the voltage between boot and PH would be reversed.. is the internal circuitry capable of handling this? i see an 8V max voltage between boot pin and PH pin in the max electrical rating table but it does not say about reverse. I've ordered a few more parts to do some experiments.. will report later.. any ways, is there suggestion to protect under such operation? thanks regards Leong
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Forum post: RE: TPS56339: TPS56339 caught fire
hi, I am looking into this request and give you feedback on Monday.
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Forum post: RE: LP8863-Q1: Led Faults
Could you offer the schematic
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Forum post: RE: TLC6C5912-Q1: About Vcc and VI voltage setting
Could you tell me why you need these condition
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Forum post: RE: TPS61032: TPS601032, capacitor shorting circuit
Hi Jasper, I attached waveform . This output is without C3 cap since it was causing short on output. Capacitor is: KEMET Part Number: T520B227M006ATE035 T520, Tantalum, Polymer Tantalum, 220 uF, 20%, 6.3 VDC, SMD, Polymer, Molded, Low ESR, Non-Combustible, 35 mOhms, 3528, Height Max = 2.1mm Thx
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Forum post: RE: BQ24617: Large current usage
Hi Kedar, Thank you so much for your advice. I understood. Best regards, Shidara
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Forum post: TPS62125: TPS62125
Part Number: TPS62125 We have an application to derive the power for the micro-controller (3.3V/10mA) from the 4-20 signal, we are considering TPS62125 for this application. Please let us know if this is the right part and share the application circuits and other details to use this converter in such applications. Also, please let us know if you have any technical details or guidelines that needs to be followed in such designs.
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Forum post: TPIC7218-Q1: Gate voltage drive on the GPR pins is NOT sufficient to provide a strong V GS
Part Number: TPIC7218-Q1 Hi, TI team I have a problem about lack of voltage on Gate voltage drive on the GPR.When i actived the gate voltage drive on the GPR, its actived but the voltage is near 7 volt,while i will expected 20 volt, because of a built-in charge pump. And I think the real cause of the issue has not be found, so I hope you can give me some additional suggestions. Thanks so much! Regards
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Forum post: RE: UCC28180: Mosfet is getting failed and load is flikkering
(Please visit the site to view this file)
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Forum post: RE: LM5145: Negative current during Diode Emulation Mode with no load
Hi, Can you figured out all the waveform in your picture represent for what voltages or currents? Best Regards, Xing
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Forum post: RE: CCS/UCD3138HSFBEVM-029: Unable to understand current temperature compensation
Thank you for your answer！I got it.
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Forum post: RE: LM5145: Negative current during Diode Emulation Mode with no load
Hi Xing， The green one is inductor current, the dark blue one is LO pin voltage，the light blue one is SW pin voltage，the purple one is syncout pin voltage.
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Forum post: Low Noise LDO Recommendation
Hello, I am making an RF amplifier for a signal in the ~micro volts range. I am trying to minimize the noise in the circuit, so I would love to get some recommendations on any LDOs, or combinations of LDOs and linear switching voltage regulators. The power supply will likely be a 6 or 12V lead-acid battery, and I am hoping to get an output voltage of ~3.3V Thank you for the help!
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Forum post: LM5176EVM-HP: LM5176 interleave mode
Part Number: LM5176EVM-HP Dear TI； Custom want to use two pcs LM5176 in interleave mode 180 degree and with external clock ? Does TI have releated reference design, If can, please advise schematic and clock IC for me, thanks.
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Forum post: UCC28C43: Flyback Converter Overcurrent Protection
Part Number: UCC28C43 I have been using this(UCC28C43) IC for my project and i want to know what would happen if my output short circuit. is IC going to turn off the converter or do I need to put overcurrent protection on the output side?
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Forum post: UCC28710: How to handle ucc28710 in a buck converter design
Part Number: UCC28710 Dear Team I'm a student from switzerland and i would like to design a buck converter (without isolated output) with the ucc28710 chip. My design should work in range of 85VAC to 275VAC input and the output should be 3.3VDC by a current around 100mA. Is the ucc28710 a ideal device for a low cost, high efficiency AC/DC converter? The datasheet from ucc28710 treated only isolated topologies, so i found your reference design for a buck converter. Do you have any datasheets who treat non isolated topologies? Next i simulated the reference design below with the ucc28710 transient model in the simulation programm TINA9, but it doesen't work. Even the start up proced doesn't work. What could be my failure? After that i bought some ucc28710 to built the reference desgin. With a DC input (up to 110V) works nothing. Then i replaced the DC input with a AC input and the diode recifier with a bridge recifier. After that i saw the start up proced by a input voltage of 20VAC(make sense). Why it doesen't work with a DC input? How can i influence the output voltage? Best Regards Sandro (Please visit the site to view this file)
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