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Discussion - Hardware / Handling the RESET# when using the FT234XD with USB self-power.
« on: February 05, 2022, 04:33:11 AM »
Hi
I am using FT234XD.
The power supply method is using the USB self-powered method.
There is an explanation to use "VBUS_SENSE" for reset in the item "6.2 Self Powered Configuration" of the specification sheet "DS_FT234XD.pdf", but it does not exist in the IC of this model.
I would like to use the Vbus from USB divided by two resistors and connect it to "RESET#" instead.
Let's consider the conditions under which USB becomes active without system power supply.
1) When the voltage is applied only to "RESET#", does it cause latch-up or other defects?
2) Is there a problem with leaving "RESET#" unconnected (OPEN) in order to avoid latch-up concerns?
Is there a possibility that the USB circuit will become inoperative because reset does not occur every time the USB Connector is inserted or removed?
The spec sheet also states that the RESET# pin can be Open when not in use.
Since the PCB is complete, I would like to know if there are any problems with methods 1) and 2) first.
I used a translation site.
I am using FT234XD.
The power supply method is using the USB self-powered method.
There is an explanation to use "VBUS_SENSE" for reset in the item "6.2 Self Powered Configuration" of the specification sheet "DS_FT234XD.pdf", but it does not exist in the IC of this model.
I would like to use the Vbus from USB divided by two resistors and connect it to "RESET#" instead.
Let's consider the conditions under which USB becomes active without system power supply.
1) When the voltage is applied only to "RESET#", does it cause latch-up or other defects?
2) Is there a problem with leaving "RESET#" unconnected (OPEN) in order to avoid latch-up concerns?
Is there a possibility that the USB circuit will become inoperative because reset does not occur every time the USB Connector is inserted or removed?
The spec sheet also states that the RESET# pin can be Open when not in use.
Since the PCB is complete, I would like to know if there are any problems with methods 1) and 2) first.
I used a translation site.