TPS92518HV: How can I get the tool to make the LEDx_TOFF_DAC time less than 10?

Brian McKee

Part Number: TPS92518HV
Other Parts Discussed in Thread: TPS92518

I'm using the TPS92518 Evaluation Board to test the linearity of the part. I'm trying to conduct efficiency tests to determine what kind of real numbers would be used in the equations to better predict the value for t(off).

I'm testing at maximum voltage at the moment and to get the target frequency I desire, 800 KHz, I need to set LEDx_TOFF_DAC to a number less than 10, but the software won't let me. It changes any number less than 10 to 10. If I set it to 10, the frequency I get is just over 500 KHz which is not fast enough to meet my ripple requirements or to test efficiency in a low head room condition.

Is there a way to make the software set LEDx_TOFF_DAC to less than 10?

Thanks.

over 7 years ago

0 Irwin Nederbragt over 7 years ago

TI__Mastermind 28655 points

Hi Brian,

I'm not sure this will work but I talked with another here. Can you try writing directly to the register for Toff?

Regards,

0 Brian McKee over 7 years ago in reply to Irwin Nederbragt

Intellectual 405 points

Thanks. That worked. Writing the desired TOFF to address 5 works. I have to disable the auto refresh though. It seems flaky if I don't. Also, the auto refresh turns back on if I move a slider without actually changing the status of the auto refresh button.

I have another question about something else, I'll start a new thread since it's a new topic.

Power management

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TPS92518HV: How can I get the tool to make the LEDx_TOFF_DAC time less than 10?