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Fails to get output on DAC1 channel 2 and DAC2

HFril.1
Associate

I feel rather stupid with this one since it should be fairly straight forward. I'm trying to use all three DAC outputs on the Nucleo32-F303K8 and I can get the first channel to work fine but I get nothing on the other channels. Multiplexing should be fine and I've removed the SB16 and 18 jumpers just in case but no dice.

I attached the registers if anyone has any ideas.

Thanks

//Henrik

0693W00000aJ8W7QAK.png0693W00000aJ8WRQA0.png

2 REPLIES 2

In contrast to DAC1_OUT1 - DAC1_OUT2 and DAC2_OUT1 are unbuffered. This means, that you have to set BOFF bit for them, and also their output current is very limited.

JW

FBL
ST Employee

Hello @HFril.1​, 

According to the reference manual RM0316, in the STM32F303x6/8 and STM32F328, the DAC1 channel 1 comes with an output buffer.

The DAC1 channel2 does not have an output buffer, it has instead a switch allowing to connect the DAC1_OUT2 to the corresponding I/O (PA5). The switch can be enabled and disabled through the OUTEN2 bit in the DAC_CR register.

The DAC2 channel1 does not have an output buffer, it has instead a switch allowing to connect the DAC2_OUT1 to the corresponding I/O (PA6). The switch can be enabled and disabled through the OUTEN1 bit in the DAC_CR register.

Hope this helps!

Firas

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