UCD3138FW-PSFB: Question: About UCD3138_FW-PSFB

user4768560

Part Number: UCD3138FW-PSFB

Hello, the DAC_SEL of the front-end 2 in the "UCD3138FW-PSFB" software code has been set up many times, but none of them uses EXT_DAC2_EN=1, so how can DAC_SEL work? I feel that some of the annotations in the software configuration instructions are very unclear. Would you like to have more detailed configuration instructions to help us learn how to use them?I look forward to your reply. Thank you.

over 6 years ago

0 Amiel Hussain over 6 years ago

TI__Expert 4070 points

Hello,

An engineer is looking into this and will respond.

0 Sean Xu over 6 years ago in reply to Amiel Hussain

TI__Genius 14580 points

Hello,

If EXT_DAC2_EN =1, DAC2 takes input from the filter selected from DAC2_SEL configuration. Here it is the zero, the DAC2 takes input from its ramp module.

Regards,
Sean

0 user4768560 over 6 years ago in reply to Sean Xu

Intellectual 375 points

Thank you very much for your answer! I can understand that the ramp is used as a reference at startup, but I see that when switching between voltage loop and current loop mode, the software is used in fast interrupts.
LoopMuxRegs.EXTDACCTRL.bit.DAC2_SEL = 4; LoopMuxRegs.PCMCTRL.bit.PCM_FILTER_SEL =0; or
LoopMuxRegs.EXTDACCTRL.bit.DAC2_SEL = 5; LoopMuxRegs.PCMCTRL.bit.PCM_FILTER_SEL =1;" implemented. But I have never found EXT_DAC2_EN=1; why? Is it not necessary to configure when using peak current mode? Is this register? Is it necessary to configure this when I use voltage mode?I hope you can elaborate on it. Thank you very much.

0 Sean Xu over 6 years ago in reply to user4768560

TI__Genius 14580 points

The bit EXT_DAC2_EN=0, LoopMuxRegs.EXTDACCTRL.bit.DAC2_SEL doesn't take effect any more. LoopMuxRegs.PCMCTRL.bit.PCM_FILTER_SEL selects which filter output to connect with DAC RAMP module. I hope this helps.

0 user4768560 over 6 years ago in reply to Sean Xu

Intellectual 375 points

LoopMuxRegs. PCMCTRL. bit. PCM_FILTER_SEL was originally used to select the ramp module. Thank you very much for solving my question!

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UCD3138FW-PSFB: Question: About UCD3138_FW-PSFB