3v3 to 5v and 5v to 3v3 on LPC1343

Development Boards MicroMod
1

I read in an arm lpc datasheet that the arm was 5v compatible providing that the vdd was on

  • does it means that I can connect a 5v output from an eprom directly to gpio pin ?

  • do I need special hardware to make sure that the 5v eprom (2532) is powered after 3V3 ?

  • apparently 3v3 to 5v is compatible (according to arm and eeprom datasheet).

any advices ? I fear to burn my LPC1343 board

thanks

2

All the recent LPC parts are 5V tolerant. And their caution is that the device should be powered on before any inputs are connected to it.

As with almost any device, the inputs will tolerate 5V if it is current limited (all 5V outputs are current limited, but if you connect it directly to a 5V power supply that would be an issue and possibly let that blue smoke out).

If you are going to drive the LPC with an output that is high before the LPC is powered up, it would be best to use a series resistor, say 1K.

3

If you are going to drive the LPC with an output that is high before the LPC is powered up, it would be best to use a series resistor, say 1K.

Thanks for your advice, it will save my LPC board :slight_smile:

I’m trying to connect old eproms to read their contents…

thanks