This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Part Number: SN6505B-Q1
My customer put SN6505B-Q1 at 85°C chamber then the output voltage became abnormal. Please find below waveforms.
SN6505B-Q1 is put at current monitoring board and closed to shunt resistor. When the board was put at chamber and large current flowed through shunt resistor, the shunt resistor's temp. is 140°C, transformer is 125°C, SN6505 is 110°C.
The measured point of scope's waveforms were as the upper diagram's, the driving waveform(CH2, green) became distortion at high temperature environment. Could them help to comment it and what experiment we can to dig out the root cause.
Thanks very much.
Hi Vincent,Thank you for including waveforms, dataset, and temperature points in this post; they are helpful in deducting a root cause here. If the SN650x system is in one of the typical configurations from the SN6501/SN6505 datasheets, then the output voltage supply might be collapsing (or distorting) due to high reverse leakage current in the Schottky diodes.At temperatures above 85dC, many Schottky diodes' reverse leakage current increases into ~1000uA range, and this too high for the system to operate properly (this is due to the current balance that must be maintained in push-pull power supplies). If our customer anticipates that their system will operate in high temperatures, please encourage them to replace the current diodes with low leakage Schottky diodes, such as the RB168MM-40.Choosing the appropriate Schottky diodes is an important consideration for push-pull power supplies as mentioned in Section 18.104.22.168 of the SN6505 datasheet. A comparison of reverse leakage currents is shown below:This is likely the cause of our customer's issue, but if there is additional information or insight I can provide, please let me know! I will await your response.Best,Manuel Chavez
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Manuel Chavez:
Thank you very much for prompt response, I will suggest customer to try another schottky diode that like you proposed and will let you know the test result.
In reply to Vincent Chen64988:
Hi Vincent,You're welcome! Has our customer implemented low-leakage Schottky diodes and tested their system? Please let me know!Thank you for your time,Manuel Chavez
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.