Hi everyone! This is Kieran from Framework, and I can shed some light into this, and our design.
First, This thread is mixing responses from a bunch of different systems, which operate very differently!
To have a discussion around each system we need to split this out into the different platform designs so we do not cross communication, which is happening a lot on this thread (This thread started as 12th gen Intel on 13in ), and has comments from Intel, AMD, 13in and 16in platforms!
To have a proper discussion around the differences please note that all our 13in systems (as of 2025) share a common charger design using a ISL9241 running in NVDC mode.
There are significant differences in how the different platforms are designed to work!
As a general statement, for type-c adapters, to meet performance we allow the CPU to draw peak power loads from the adapter + battery. This is required to achieve peak performance on AC.
First for 13in notebooks:
The charger design generally follows the diagram from above:
We do not enable BYPSG path, and the charger always operates in NVDC mode.
Please do not attempt to turn off BGATE as suggested above! The body diodes in the FETs are only rated for 1-2A, and can be damaged if you turn off these with the system under load!
For 16in AMD Ryzen 7040, we have a much more complex charger design that uses the same ISL9241. However it can operate in either bypass mode (BYPSG enabled), or NVDC buck-boost mode.
When operating in EPR mode (above 20V) it is behind by a 2 phase TI buck converter that regulates 28V-48V down to 20V.
When operating in SPR mode, the ISL9241 is connected directly to the input.
When connected to adapters 100W or below, it operates in NVDC mode.
When connected to adapters > 100W, it operates in bypass mode + reverse turbo. However during peak GPU+CPU current draw it takes a few hundred microseconds to turn around the current from charging the battery to discharging the battery for reverse turbo, which can result in high current transients passed to the charger. Our 180W and 240W adapters are designed to support this as they have a USB-IF standard defined overload spec of 150% for 1ms (which is advertised in the PDO).
For 16in AMD AI 300
We have a TI dual phase buck-boost converter that does not support bypass mode, and operates in NVDC mode always. This helps reduce peak current draw from adapters as it can respond to high current draws on the battery instantly when connected to EPR adapters.
It is proceeded by a 3 level buck converter which is used to step down the input voltage to the battery charger controller when operating at 48V. At 36V and below the 3 level buck converter is switched into bypass mode.
I am out of time for the moment, but will respond more later.