REGSRC BQ76930

REGSRC( 6-25V) should continue to operate in heavy load( via the REGOUT) and short circuit conditions and drive the FET outputs . In the bq76930, the BAT pin >> V( REG SRC). A source follower FET topology, will let REGSRC to operate ~ (Vgs -Vth) with respect to gate voltage-VC5X. BTW, VC5X and VC10X are heavily filtered (Rf, Cf) robust references. Yes, you can use the Cell9 ( with similar filters for the Gate Control of the Source follower-FET). The current for REGSRC comes from the top cell stack and voltage is dropped across the source follower FET. REGOUT max current ~20mA( 2.5V ver)
If BOM cost is not an issue, REGSRC can be powered by external regulator. If the regulator is hooked to the REGSRC, the regulator should have the ability to respond to various condition. Examples like, when the REGOUT is shorted, to keep DSG/CHG signal high.

Thank you

In the datasheet page 13 normal mode and when CC active Icc_regsrc max current 120 uA can you explain to me what does this value mean ?

When the CC is running, current will be drawn from REGSRC. The specification shows the amount.

REGSRC will also power other circuits. REGSRC is a source for the series regulator output REGOUT, so any current drawn from REGOUT must go in REGSRC.

As an additional piece of information,
REGSRC is a power-supply total separate from the BAT pin. REGSRC powers the FETS o/puts, CC, I2C and external loads thru the REGOUT ( 2.5V/20mA, 3.3V/20mA) regulators

Can you explain to me please why you add 100k resistance before the gate of the FET in th EVM board (R10 ), thank you

Rg typically is to avoid additional discharge of power filter caps. It controls the currents into the gate and also provides R||C filter.