TLV62569: Behavior when 5V suddenly applied to output in PFM mode

Hi,

We do not recommend using the PSpice model with LTSpice and do not provide support for LTSpice related issues.

Best Regards,

Zakir

literally none of my question has anything to do with LTSPICE. 

Im asking about the behavior of the device in PFM mode wrt highside mosfet. 

Hi,

I was radicalized by Altium Designer said:

I am running the sim and curious about the condition. lets say the ic is operating in PFM mode and my target voltage is 1.5V. 

Suddenly i slip and fall and accidentally force 5V on the output. 

From datasheet, if we see the absolute maximum ratings of the device then its mentioned that we cannot apply voltage more than Vin+0.3V at SW pin which would damage the device. Therefore we would not recommend operating the device at such condition. 

I was radicalized by Altium Designer said:

From what i can tell, actually the part will not sink any current at all. Because the lowside mosfet is not used in PFM mode for efficiency purpose.

Yes, the part would not sink any current because the low side FET would turn off as soon as it sees zero current.

I was radicalized by Altium Designer said:

And low side mosfet it will be off as well because the vfb voltage is too low. right ? 

The low side mosfet would be off due to current <= 0A but at this condition VFB voltage would be too high.

I was radicalized by Altium Designer said:

From sim, it appears the pfm stops immediately, and the 3.2A reverse current is literally only from charging the input capacitor thru highside mosfet body diode. 

let me know if my understanding is correct. 

At such situation, the high side FET body diode would conduct and it would damage the device depending upon for how long the diode conducts.

Let me know in case of additional concerns.

Best Regards,

Zakir