2014-04-18 10:24 AM
Hi,
You probably already get such discussion.I am currently designing a board based on STM32F103RC6 MCU that I want to supply with Vbat=3V6, VDD1/VDD2/VDD3/VDD4=VDDA= 2V4 but in the data sheet, the Vdd min in the USB DC electrical characteristic table is given at 3V0. I looked on the different evaluation board schematic, all of them configure the STM32F103 VDD supply at 3V3 which is not helpful.Knowing that I have to control the 1K5 pull up resistor to USB D+ with the STM32, could you help me on the USB schematic for my supply configuration? Should I set:- VDD1/VDD2/VVD3/VDD4=2V4 and USB D+ pull up to 2V4 or - VDD1/VDD2/VVD3/VDD4=2V4 and USB D+ pull up to 3V3.Thanks in advance for your helpRegardsBertrand