No. The MAX3420E includes an internal level translator. The VL pin provides the power for the internal logic and acts as the reference voltage for signals on the SPI and IO pins. For a 2.5V interface, the VL pin needs to be connected to a 2.5V power supply. VL pin can operate at voltages between 1.7V and 3.6V. Alternatively, if the controller uses a 3.3V power supply as well, connect VL to VCC.