The MC145407 is a silicongate CMOS IC that combines three drivers and three receivers to fulfill the electrical specifications of EIA232E and CCITT V.28 while operating from a single + 5 V power supply. A voltage doubler and inverter convert the + 5 V to 10 V. This is accomplished through an onboard 20 kHz oscillator and four inexpensive external electrolytic capacitors. The three drivers and three receivers of the MC145407 are virtually identical to those of the MC145406. Therefore, for applications requiring more than three drivers and/or three receivers, an MC145406 can be powered from an MC145407, since the MC145407 charge pumps have been designed to guarantee 5 V at the output of up to six drivers. Thus, the MC145407 provides a highperformance, lowpower, standalone solution or, with the MC145406, a + 5 V only, highperformance twochip solution. Drivers