Convoy 8A buck driver uses the MPQ8612-12
While it’s a high current converter with fairly low Rdson FETs I don’t think it’s a good choice for flashlights because it’s not 100% duty cycle capable. The MCU is from Sonix, the firmware is proprietary.
17mm buck driver is possible of course, especially with high frequency buck converters. This is a 18mm, 14mm clearance one I made for the FWAA , it’s double sided but it has a RPP PFET and 2 sense resistors for high dynamic range and Aux LEDs, without this it could be one sided.
I used the TPS62867 (11mΩ,10.5mΩ, 2.4MHz, 6A), it is AFAIK the best buck converter for 1S to 1S as of today, unfortunately all TI DC-DC offering is out of stock until 2023. Another good option is the MP2145 (20mΩ,12mΩ, 1.2MHz, 6A), I designed a 22mm, 18mm clearance one and tested it, also one for the FWAA, with 16mm clearance :
Again getting rid of HDR, RPP FET and Aux LED pads it would fit in 15mm clearance (17mm total diameter) on one side, maybe even while keeping RPP.
Here is the schematic :
(Q2 and R7 can be removed if moonlight modes aren’t needed).
Note that it uses the DAC of the T1616, removing the need for a LDO, battlevel resistor divider, LPF filter for PWM, Convoy drivers all use filtered PWM to set the current sensing voltage and so have these additional components.
Of course for the S2+ you need to add either OTC or OTSM for the clicky switch as well as use an appropriate firmware, since my drivers are for e-switches. Gchart metionned in the Attiny 1 series thread that he tested a clicky firmware IIRC, using PWM, I don’t think work as been done on a DAC controlled T1616 clicky firmware.
That RT8073 looks pretty bad, no way that it can do 6A with 50 and 35mΩ FETs.