LP-MSPM0L2228: VREF can't be activated via SYSCONFIG

stanley liu

Part Number: LP-MSPM0L2228
Other Parts Discussed in Thread: SYSCONFIG, MSPM0G3507

Tool/software:

Hi Expert

i used LP-MSPM0L2228 to do my project, i want use 2.5V Vref to my external device, when i enable Vref in sysconfig(P2)

i can't measure 2.5V(PA23/pin 72) in my multimeter, my previous project was MSPM0G3507(P1) and i can measure 2.5V(PA23/pin 24)

in my multimeter and I noticed i can't specify VREF pin function in CCS20 sysconfig.

0 Helic Chi 4 months ago

There are small difference between L series and G series's VREF module, please refer to their's TRM

Also, here is the config that you can try, but refer to the TRM, I don't think bring internal Vref to external is possible:

0 stanley liu 4 months ago in reply to Helic Chi

Hi Helic

thanks for your help, i follow your setting and test, it really can't output 2.5V to PA23

and i also add a COMP in sysconfig try to guide reference voltage output, it still doesn't work,

output reference voltage is very important for this project, Is there really no other way?

+1 Helic Chi 4 months ago in reply to stanley liu

stanley liu said:
output reference voltage is very important for this project, Is there really no other way?

You can use PWM with external RC filter to generate a voltage reference.

0 stanley liu 4 months ago in reply to Helic Chi

Hi Helic

thanks for your help, i got it

0 Helic Chi 4 months ago in reply to stanley liu

There is no way to source a COMP DAC8 to external in L2228.

You can use G3507's COMP DAC8 + OPA to output a DAC8 to external pin.

0 stanley liu 4 months ago in reply to Helic Chi

Hi Helic

i don't need COMP function, i just want to try guide the 2.5V reference to output

thanks for your reply.

+1 Helic Chi 4 months ago in reply to stanley liu

Just mention the difference between G3507 and L2228.

It seems that PWM to DAC is your only choice.

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