The ISL4243E features an automatic power-down function that powers down the on-chip power-supply and driver circuits. This occurs when an attached peripheral device is shut off or the RS-232 cable is removed, conserving system power automatically without changes to the hardware or operating system. It powers up again when a valid RS-232 voltage is applied to any receiver input. Table 1 summarizes the features of both the ISL4241E and ISL4243E, while Application Note AN9863 summarizes the features of each device comprising the 3V RS-232 family.