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In any switching regulator, conventional time-based soft- starting can be defeated if the input voltage rises much slowerthan the time out period.This happens because the switching regulators in the battery charger and the com- puter power supply are typically supplying a fixed amount of power to the load. If the input voltage comes up slowly compared to the soft-start time, the regulators will try to deliver full powerto the load when the input voltage is still well below its final value. If the adapte r is cu rrent limited, it cannot deliverfull power at reduced output voltages and the possibility exists for a quasi "latch" state where the adapter output stays in a current limited state at reduced output voltage. For instance, if maximum charger plus computer load power is 25W, a 15V adapter might be current limited at 2A. If adapter voltage is less than (25W/2A = 12.5V) when full power is drawn, the adapter voltage will be pulled down by the constant 25W load until it reaches a lower stable state where the switching regu- lators can no longer supply full load. This situation can be prevented by utilizing undervoltage lockout, set higher than the minimum adaptervoltage where full power can be achieved.