Hi Power Folk,
Could you clarify how current limit is triggered in LM5576?
From datasheet, I understand the cycle by cycle current limiting is triggered when peak current sensed from diode current (highlighted in yellow below) reaches at 4.2A. The peak current sensed from diode current would be Iout + △Iinductor/2.
When I run the TINA simulation, I notice that the current limit is already triggered when Iout = 2.5A and △Iinductor = 1A. As you can see, IL waveform has its peak at 3.12A and Vout is lower than target voltage (28V) because of the current limiting behavior of LM5576. Could you help clarify how 3.12A of low inductor current triggers the current limit?
Please find the tina simulation file for more detail.
LM5576_22uH_snvmbp5_211222 .TSC
Thank you.
