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LT8711 LTSpice model issue

Question asked by PShepherd on May 8, 2018
Latest reply on May 8, 2018 by victor.khasiev@analog.com

Is this a bug in the LT8711 LTSpice model, or have I set it up incorrectly?
The LT8711 is hiccuping because the IntVcc pin is hitting its UVLO threshold (3.9V). The current into the pin is spiking between 200 and 400mA while the circuit is switching, and these current spikes draw the voltage on the capacitor down. Putting a very large cap value on the pin delays the UVLO shutdown, but eventually it still hits the UVLO trip point. Adding a small series resistor to the pin doesn't reduce the magnitude of the current spike that goes into the pin, so I am guessing the macromodel may have a current source on this node with no Norton resistance.

 

Thanks in advance!

(LTSpice version is April 2nd, 2018)

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