What is LDO mode?
In the case where there is no battery in the portable device, the device can still operate with the wall adapter plugged in the outlet or with the car adapter activated. The LP3947 detects the absence of a battery and automatically configures the internal charger circuit as a linear regulator that acts as a power supply to the portable device. The supply voltage is equal to the termination voltage of the battery. This feature is valuable as manufacturers don”t require a battery during assembly test.