Spi Level Shifter


I’m designing a lora gateway with the sx1302 pcie spi version module and am62 Mallow board.

This module require 5v signals.

I tried the tx0104 bi directionnal level shifter but the signals shape are really not clean…

Whitch reference do you advices for this application pleas?

Did you remark this kind of issue or improvement with uni directionnal level shifter ?

Thank you !

According to the datasheet for the SX1302 IC, its host interface is designed to operate at voltage levels ranging from 3.0 to 3.6 volts. Since your module requires a 5V interface, it is likely that it already incorporates 3.3V to 5V voltage level shifters. To prevent the need for double voltage shifting, I recommend selecting a LoRa module that natively supports a 3.3V interface. In this case, you could use SN74AVC4T245 voltage level shifters, which are capable of maintaining significantly better signal integrity compared to TXB0104. The optimal solution would be to find a LoRa module with a 1.8V interface, as this would further enhance compatibility and efficiency in your setup.

Hi @alex.tx ,

Thank you for the fast reply.

I slow down the frequency to 500khz, but it doesn’t improve at all.

As there is not a lot of indutrial serious module like the embit i’m using ( emb-lr1302 ) , I would like to keep this reference and choose a better level shifter. Also, other module are also supplied with 5V.

By looking at the portfolio of texas, I can find more dedicated device like the TXU0304. The biggest difference with my actual TXS0108E is the uni dictectionnal feature and 4x faster.

Please double-check the module’s specifications and/or schematic. Although many SX1302-based modules require a 5V power supply, they typically feature a 3.3V IO interface.