GPIO state Of STM32L071

[SJ.8]

Hi,

I am using STM32L071CBT6 with VDD,VDDA,VDDIO2 supply Voltage of 1.8V , Please refer above image, i am using PB6 as GPIO ,initially it is configured as push-pull output , we are getting 0 to 2V output swing, when we changed GPIO to Open Drain with pull-up & Open drain with no pullup and no pull down , in both configuration we are getting 0.2V constant. I need output Voltage swing between 0V to 5V as per requirement. I am toggling GPIO 200ms on/off. Any suggestion?

Regards,

Srinivas

[Michal Dudka]

If MCU GPIO is connected "on right" side of your schematic. Then there is a simple answer. Your output is loaded (or short circuited) on left side of R233. Push pull output can drive 3k9 load and reach 1.8V. In open drain mode external (R232) or internal pullup creates voltage divider with R233.