Applikations­schriften

The Enable input (EN), available in positive and negative logic, turns the device on and off by an external signal. Active-high logic activates the device when the voltage at the EN-input exceeds the high-logic threshold. The active-low logic switches the device off when the EN-voltage falls below the logic low threshold. The EN-function is an import- ant feature when sequencing power supplies in multi-rail systems.

When the LDO is turned off and connected to the battery system, the input current will be limited, usually up to 1 µA. This Shutdown current is commonly confused with the quiescent current which is the current drawn by the device when it is enabled and opera- ting with no load. Both shutdown and quiescent current are important parameters when realizing long battery lifetimes in portable devices.