You piqued my interest as to how the FT230X managed this point... From a quick read of the datasheet, it looks like that by default the chip tells the USB bus that it's in a bus-powered device that only needs 90mA. The datasheet is short of detail, but the implication is that you can change this value by writing to the internal EEPROM (see section 8). There's also discussion elsewhere in the datasheet about how to manage the requirements of being a bus powered device, including configuring one of the CBUSn pins to the PWREN# function so you can signal your MCU as to whether you got your power request or not.
Neat chip! Jon. On Wednesday, February 17, 2021 at 9:00:59 AM UTC newxito wrote: > Nice clock! > In my circuit, the USB data lines are not connected to the MCU. Actually, > I expect that the negotiation will be done by the FT230X (USB to basic UART > IC), maybe I’m wrong. > When plugged in, the device should only consume a few mA, I will delay > powering on the nixies. For the HV, I use a flyback design with a LT3757 > that has a soft-start function, so I don’t expect spikes over 500mA. With > the nixies and neons powered on, the device should not consume more than > 400 mA. That’s the theory… > I will follow your suggestion and use a hub for testing, thanks Jon. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/5c317dd7-d06e-4b16-afa3-26fdc0a5bd35n%40googlegroups.com.
