RS-232收发器具有增强的自动断电和一个单独的逻辑电源ISL83387E

　　The Intersil ISL83387E is a 3.0V to 5.5V powered RS-232 transceiver which meets ElA/TIA-232 and V.28/V.24 specifications， even at VCC = 3.0V. Additionally， it provides ±15kV ESD protection （IEC61000-4-2 Air Gap and Human Body Model） on transmitter outputs and receiver inputs （RS-232 pins）。 Targeted applications are PDAs， Palmtops， and notebook and laptop computers where the low operational， and even lower standby power consumption is critical. Efficient on-chip charge pumps， coupled with manual and enhanced automatic powerdown functions， reduce the standby supply current to a 1µA trickle. TSSOP packaging， and the use of small， low value capacitors ensure board space savings as well. Data rates greater than 250kbps are guaranteed at worst case load conditions. The ISL83387E features a VL pin that adjusts the logic pin output levels and input thresholds to values compatible with the VCC powering the external logic （e.g.， a UART）。 This device includes an enhanced automatic powerdown function which powers down the on-chip power-supply and driver circuits. This occurs when all receiver and transmitter inputs detect no signal transitions for a period of 30 seconds. It power back up， automatically， whenever it senses a transition on any transmitter or receiver input. Table 1 summarizes the features of the ISL83387E， while Application Note AN9863 summarizes the features of each device comprising the 3V RS-232 family.