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DAC via opamp follower

GeertZelf
Associate III

Hi all,
I am in the process of bringing up a prototype board with a STM32L4R7ZIT6 up. I'm using one DAC channel via the opamp. This is working all right, until I designate the default output of the DAC to another function e.g. dig output. 

The DAC is configured as 'only to on chip peripherals.' If the io-pin is at reset state, the output voltage appears at the opamp output pin.

I am using CubeMX for generating the startup code. 75% of the IO is configured. I hope someone has a clue.

10 REPLIES 10
RichH81
Associate II

Thanks GeertZelf. I ended up moving LTDC_R4 (red channel 4) over to PA11(? I think) which allowed me to use DAC1_OUT2 (w/o the op amp) on PC3 (? I think). Vsync on PA4 and LTDC_R4 are working as is DAC1 using its second channel. Agree, I think the on-chip peripheral option for DAC1 is broken on the chip. Luckily we're at the PCB prototype stage so can make a change like this with no impact.