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Title: 3V SPI/I2C voltage translation [Print This Page]

Author: Konrad.Z    Time: 1/31/2018 15:59
Title: 3V SPI/I2C voltage translation
I want to connect my MCU that run on 3.3V with your board via SPI and I2C, but FireFly voltage level on these buses is 3V. Will I need voltage translation or will it be on spec with FireFly ?


Author: leungÏÈÉ­    Time: 1/31/2018 17:00
Basiclly, 3.3v is the same as 3v .
But if your MCU is serious about voltage controled, just try apply 3v to your MCU.
I trust your MCU have its Float voltage.
Author: Konrad.Z    Time: 1/31/2018 19:46
Ok, thanks.
Author: big_whit    Time: 2/5/2018 03:13
Does anyone actually knows if the RK3399 VDDIOs bank @3.0V are Voltage tolerant to VDD+0.3V . Trying to find the information in the RK3399 datasheet but can't find anything.

As per the RK3399 carrier board schematic - the UART2DBG_RX net it directly tied to a 3.3V pullup and the IO bank is set to 3.0V. Any long term issue with this ?
Author: leungÏÈÉ­    Time: 2/5/2018 09:35
big_whit Posted at 2/5/2018 03:13
Does anyone actually knows if the RK3399 VDDIOs bank @3.0V are Voltage tolerant to VDD+0.3V . Trying ...

u can try to set up the group gpio of the UART2DBG_RX  from the hardware datasheet.
It is controled by pmu.




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