Suggest a constant current regulator which can source 20A current and support a voltage output of minimum 100V.
If modification is made, can i use LT3763 to operate at 100V like by using GATE drivers.
LT3763 can’t handle 100V output. The maximum voltage rating for SENSE+ and SENSE– pins is only 60V.
The only IC to survive 100V output is LTC3779 which can also work as a current source.
Please check if it meets your requirement.
If i need to design 14A constant current source which can be tuned from 0A to 14A current at maximum rated voltage input as well as output of 150V, what change should be done to figure in last page of http://cds.linear.com/docs/en/datasheet/3779f_%281%29.pdf . Constant current regulation is bit unclear in data-sheet, kindly clarify . What is the effect of Vfld. How Ith should be controlled. What about LTC3796 IC to regulate current at 100V with 14A.
Thanks & Regards
The LTC3779 output current loop is not design for controlled current source used in LED application. It is mainly used as output current limit function. Please check other ICs to meet your requirement.
In LTC3779 data-sheet it is mentioned, " Constant-Current Regulation (IAVGSNSP and IAVGSNSN Pins)The LTC3779 provides a constant-current regulation loop for either input or output current. A sensing resistor close to the input or output capacitor will sense the input or output current. When the current exceeds the programmed current limit, the voltage on the ITH pin will be pulled down to maintain the desired maximum input or output current. "
Kindly explain the above.
Also Fil mentioned that " The only IC to survive 100V output is LTC3779 which can also work as a current source. "
If LTC3779 can't be used, suggest an IC which can be used as constant current regulator to regulate current of 14A at 100V.
What about LT3796 or LT3756 IC to regulate current at 100V with 14A. Please reply asap.
Basically, if the output current reaches the set output current limit, the output current loop will function and make sure it won't go beyond. Otherwise the voltage loop will function to regulate the output voltage. If you have a voltage source output such as a battery, by setting the regulated output voltage higher than the battery voltage, you can make the converter operating as a constant current source with the current equal to the output current limit. For more detailed spec. related questions, please contact our local FAE for more help.
Kindly explain " Constant-Current Regulation (IAVGSNSP and IAVGSNSN Pins)The LTC3779 provides a constant-current regulation loop for either input or output current. A sensing resistor close to the input or output capacitor will sense the input or output current. When the current exceeds the programmed current limit, the voltage on the ITH pin will be pulled down to maintain the desired maximum input or output current. " which is given in data-sheet of LTC3779. As per the discussion with your local FAE, he confirmed that LTC3779 can be used as constant current source (with reference to figure in last page of data-sheet) and mentioned it can be used to deliver constant 10A current at maximum 48V output but he was not sure about how to maintain constant current.
Also Lt-spice file for this part is not working, screen shot of error message is attached in above post.
LT-powercad also don't have this part, kindly update software asap.
If this IC is not the right part kindly update your local FAE and suggest a part to implement requirement given in question.
Regards & Thanks
Please let me know who is the local FAE you discussed with. I will contact him and work together with him to help you.
It is praveen jose and rohit tickoo. Please ask them to suggest the best part asap.
I'm getting error in LTspice while opening LTC3779 file, Screen-shot is attached. Let me know how to fix this error.
Retrieving data ...