FTDI Community

Please login or register.

Login with username, password and session length.
Advanced Search  

News:

Welcome to the FTDI Community!

Please read our Welcome Note

Technical Support enquires
please contact the team
@ FTDI Support


New Bridgetek Community is now open

Please note that we have created the Bridgetek Community to discuss all Bridgetek products e.g. EVE, MCU.

Please follow this link and create a new user account to get started.

Bridgetek Community

Author Topic: FT230XS  (Read 105 times)

mikes603

  • Newbie
  • *
  • Posts: 1
    • View Profile
FT230XS
« on: January 05, 2021, 02:26:48 PM »

Hi Gents,
 I had/have an issue where our FT230XS is supplying current into our MCU over the FT230XS's TX and RX lines. And keeping the MCU a bit alive across reboots. Some current limiting resistors seem to be needed on these two lines. But I'm curious if this is a common issue / known limitation. Are series resistors the suggested design? And what is going on with the FT230XS whereby it can supply current on TX/RX?
Logged

FTDI Community

  • Administrator
  • Hero Member
  • *****
  • Posts: 542
    • View Profile
Re: FT230XS
« Reply #1 on: January 06, 2021, 04:47:15 PM »

Hello,

Can you please email your local support team and we can look into this issue further?

https://www.ftdichip.com/FTContact.htm

Then you can post any resolution here to help other community users.

Best Regards,
FTDI Community
Logged

cioma

  • Newbie
  • *
  • Posts: 12
    • View Profile
Re: FT230XS
« Reply #2 on: January 09, 2021, 10:37:59 AM »

It's a known phenomenon in electronics: unpowered chip gets powered trough its internal ESD protection diodes when its signals are driven high.
The right way to deal with it is to use buffers with so-called Ioff feature (e.g. TI SN74AUP1G34) or a dual-supply voltage translators (e.g. ON FXMA2102).
Using series high-value resistors is not ideal as it will make signal edges very slow.
Logged