USB_PWR is connected to rocker switch, that switches between usb power and battery power.USB_PWR is connected to rocker switch, that switches between usb power and battery power.
3V3OUT connected to get 3.3v internally generated from ic.
When am powering the circuit from the battery, txd and rxd are sending some data which is giving voltage to ft232rl thus making ds3 LED glow.
A rocker switch, whose bright idea was that?
3V3OUT connected to get 3.3v internally generated from ic.
Great so you have a low impedance path from a 3.3 Vout output to a source of +5 Volts and you wonder why the chip is having problems.
When am powering the circuit from the battery, txd and rxd are sending some data which is giving voltage to ft232rl thus making ds3 LED glow.
Only one of them can have a signal that sources or sinks current, and I don't believe there is enough enough current coming out of a GPIO pin to damage the protection diodes in the FT232RL. The question is what state is USB_PWR in and what voltage can be measured on USB_PWR and 3V3OUT which are shorted together and all by itself is enough to cause major problems.