Attached files are schematic and waveform.
CH1：LREG1 current ；CH2：RST4 reset；CH3：supply_on_1（ EN1 and EN2）
Customer find the RST4 always generate the reset signal when MCU enable the EN1/EN2 .
If they make the EXTSUP(pin40 of TPS43340)open which means they disconnect this pin40 from PCB, the failure issue will disappear.
So customer wonder why the EXTSUP would influence the RST4.
Customer want to know why there need add a diode between the EXTSUP and 5V Buck?
If there do not add the diode and connect EXTSUP with 5V Buck directly , what is the risk?
