LM5019: COT Crossover Frequency

Michael Balourdas

Expert 5335 points

Part Number: LM5019

Hello,

What is the target/expected crossover frequency for COT devices like LM5019?

Thanks,

Michael

over 2 years ago

0 Elena Gao over 2 years ago

TI__Genius 13735 points

hi,

crossover frequency of COT device is hard to tell from calculation , usually we get the result from real test on board. like loop test and transient test to confirm the stability.

Elena

0 Michael Balourdas over 2 years ago in reply to Elena Gao

TI__Expert 5335 points

Hi Elena,

Is there a minimum/maximum value to be considered "stable"?

Thanks,

Michael

0 Elena Gao over 2 years ago in reply to Michael Balourdas

TI__Genius 13735 points

hi, Michael,

The direct way is to do a loop test, show here (How to Measure the Loop Transfer Function of Power Supplies (Rev. A))

Stability Conditions:

Sufficient phase margin is required to prevent oscillations. A phase margin of 45 degrees or greater is the design goal. A gain margin of –10 dB at least is the is considered good.

Elena

Power management

Power management forum

LM5019: COT Crossover Frequency