This recently added Logic Level Converter is no exception. It’s uses two BSS138 MOSFETs to shift 5V logic levels to 3.3V. The board handles two separate serial pairs.

see the entire 3.3v to 2.5v/5mA , REG, Linear Regulator, UMC 55nm LP/RVT Logic Process datasheet get in contact with 3.3v to 2.5v/5mA , REG, Linear Regulator, UMC 55nm LP/RVT Logic Process Supplier ...

4-Level Voltage Detector for USB-OTG ; UMC 55nm 2.5V overdrive 3.3V device LP/HVT LowK Logic Process ...

You’ve got several devices which communicate via the I2C protocol, but some of them can only operate at 3.3V while the rest are hungry for a 5V connection. What to do? [Linux-works] built thi… ...

The devices are said to reduce power consumption by at least 50% each if the losses in dc/dc converter circuits are included.