My customer wants to convert 110~140V input to 100V/0.1A output with a LDO. The high voltage LDO is too expensive so customer wants to use LM317 to do a low cost solution. But LM317's max input voltage is less than 110V. So I want to check with you can we make a floating GND for LM317 GND pin so it can endure 110V input to the system GND? Do you have such design experience? Thanks.