FTDI Community
General Category => Discussion - Hardware => Topic started by: gripennn on September 19, 2022, 08:31:00 AM
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Hi,
i am drawing PCB with FT601 and i am confused about VBUS pin.
In datasheet
https://ftdichip.com/wp-content/uploads/2020/07/DS_FT600Q-FT601Q-IC-Datasheet.pdf
at Figure 6.1, 6.2, 6.3, 7.1 and 7.2 is VBUS connected directly to USB +5V.
In UMFT60xx module schematic
https://ftdichip.com/wp-content/uploads/2020/07/DS_UMFT60xx-module-datasheet.pdf
is VBUS pin connected to USB +5V through 4k7+10k divider.
What is the right way to connect VBUS pin ? And what is purpose of that pin (datasheet only claims "USB BUS power input") ?
Thanks,
Michal
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Hi Michal,
The recommended way of connecting VBUS depends on your application:
(a) For self-power application, refer to the UMFT600x/UMFT601x datasheet (https://ftdichip.com/wp-content/uploads/2020/07/DS_UMFT60xx-module-datasheet.pdf);
(b) For bus-power application, VBUS is the 5V power input for all circuits. If a 5V to 3.3V regulator is used, connect the 3.3V to the FT601 VBUS pin.
Note, the voltage divider in the Development Module between the USB power and VBUS pin is used to lower the voltage level from 5V to 3.3V so that FT601 can take it as a 3.3V logic input for VBUS sensing purpose.
If you haven’t already, please refer to AN_412 FT600/FT601 Bridge Chips Integration (https://ftdichip.com/wp-content/uploads/2020/08/AN_412_FT600_FT601-USB-Bridge-chips-Integration.pdf). This application note is for designers who want to integrate the FT60x into new designs. As well as this have a look at our FT600Q-FT601Q SuperSpeed USB3.0 IC Datasheet (https://ftdichip.com/wp-content/uploads/2020/07/DS_FT600Q-FT601Q-IC-Datasheet.pdf) and Technical Note TN_168 FT600_601 Errata Technical Note (https://ftdichip.com/wp-content/uploads/2020/07/TN_168_FT600_601-Errata-Technical-Note.pdf).
Best Regards
FTDI Community