- When resistor R2 is not used:
In this case, when the VBUS supply voltage is removed, the voltage across the capacitor takes a longer time to discharge itself. During this period, if the VBUS is applied again, there is no RESET pulse on the pin. This means that the external reset is released before the hub's internal reset which is not recommended.
- When resistor R2 is used:
In this case, when the VBUS supply voltage is removed, the voltage across the capacitor discharges through the resistor R2. Hence, when the VBUS is re-applied, the reset pulse gets applied on the RESET pin. This is the reason behind having a resistor R2.
Hello Srinath san
Regarding the circuit diagram I attached before. Although it is described as R2 in the answer, this is the understanding of R43, is it correct?