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LTC4368 - SHDN goes low and output switched on

Category: Hardware
Product Number: LTC4368


we are using the LTC4368 and it works very well. The circuit looks like I posted below. 

The circuit works except the one following case. For some days I made some measurements and get a weird behavior. The ltc4368 switched off his output, because of an OC condition. The output voltage is still around 2V, because of rest charge inside the output capacitors. When I switched the SHDN pin to low the gate voltage and output voltage increased. Looks like the LTC4368 switched the gate on. But I have no idea why. I would expect that the gate will be pull to low and the output voltage decrease or will be hold on around 2V. 

Looks like it happened when the output voltage is greater then the gate voltage.

Do you have any idea ?

yellow: enable signal = SHDN, connected to a controller
dark blue: output current
light blue: gate voltage
red: output voltage

Best regards