Provide ±15kV ESD protection on transmitter outputs and receiver inputs (RS-232 pins). Targeted applications are PDAs, Palmtops, and hand-held products where the low operational power consumption and even lower standby power consumption are critical. Efficient on-chip charge pumps, coupled with manual and automatic powerdown functions, reduce the standby supply current to a 150nA trickle. The 5mmx5mm Quad Flat No-Lead (QFN) packaging and the use of small, low value capacitors ensure board space savings. The ISL4221E is a 1 driver, 1 receiver device and the ISL3232E and ISL4223E are 2 driver, 2 receiver devices that, coupled with the 5mmx5mm QFN package, provide the industry’s smallest, lowest power serial port suitable for PDAs, and hand-held applications. Automatic powerdown occurs when an attached peripheral device is shut off or the RS-232 cable is removed, and conserves system power automatically without changes to the hardware or operating system.