TPS56121

eli

Guru 13485 points

Other Parts Discussed in Thread: TPS56121, TPS56221

Iplanning use Pin 21 (EN/SS) such as PWM control signal 50Hz for output power.Can its be done?

over 9 years ago

0 JohnTucker over 9 years ago

TI__Guru**** 191445 points

Applying a 50 Hz signal toSS/EN will restart the converter every 20 msec, assuming very narrow negative pulse.your SS time is 19.8 msec. You will see your output voltage as a triangular ramp waveform assuming your load can completely discharge the output voltage in the short EN off time. I doubt that is what you are trying to achieve.

0 eli over 9 years ago in reply to JohnTucker

Guru 13485 points

Thanks.

Can this application damage TPS56221/TPS56121?

This is the main problem ???

0 JohnTucker over 9 years ago in reply to eli

TI__Guru**** 191445 points

Can you tell me more about your application? Maybe I can give you a better answer.

0 eli over 9 years ago in reply to JohnTucker

Guru 13485 points

connect to output TEC see attached file and Pin enable I connect to PWM controller (50 Hz) for control power of TEC

0 eli over 9 years ago in reply to eli

Guru 13485 points

See attached TEC d/s.

Ferrotec 9500 071 085 .pdf

0 JohnTucker over 9 years ago in reply to eli

TI__Guru**** 191445 points

I'm still not sure what you are trying to do. Are you trying to get a ramp waveform output for the TPS56121? Or just trying to vary the output voltage over a range? If you are trying to vary the output, it is best to do that by injecting current into VFB. You can do that with a filtered PWM signal.

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TPS56121