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Author Topic: FT230XQ: Powering VCC with 3.3V  (Read 9089 times)

zeedel

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FT230XQ: Powering VCC with 3.3V
« on: February 04, 2020, 10:36:34 AM »

Hi,

I am integrating the FT230XQ chip into my design, and am powering VCC with 3.3V (regulated from USB_VBUS). Consequently, I followed the datasheet which states "3V3OUT on pin 8 is an input pin and should be connected to pin10". Please could you advise whether the attached schematic is correct? I should highlight that the 3.3V rail supplying VCC, VCCIO, and 3V3OUT is derived from USB_VBUS using an LDO regulator.

Thanks.
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FTDI Community

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Re: FT230XQ: Powering VCC with 3.3V
« Reply #1 on: February 04, 2020, 02:10:19 PM »

Hello,

Yes those power connections are correct as the datasheet states, if VCC is 3V3 then 3V3OUT must also be driven with 3V3 input.

You may also want to include 47pF capacitors on the USB lines for edge rate control.
See AN_146 USB Hardware Design Guidelines for FTDI ICs for more details.

We have Development Modules available for test, evaluation and reference.

Best Regards,
FTDI Community
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zeedel

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Re: FT230XQ: Powering VCC with 3.3V
« Reply #2 on: February 05, 2020, 10:53:15 AM »

Thanks so much, the response has been very helpful. Indeed, I had overlooked the need for the 47pF edge rate control capacitors.
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