Electronically Switchable Interface Circuit With Multiple EIA Protocol Drivers and Receivers
Original Publication Date: 1988-Apr-01
Included in the Prior Art Database: 2005-Feb-15
This article describes multiple protocol drivers/receivers which provide switchable electrical interfaces, such as RS232, RS422 and V.35, on communications attachment cards and which enable reduction in size of the cards. The circuit offers advantages over existing interface circuits in that the RS232, RS422 and V.35 EIA interface drivers/receivers are configurable, under program control, from a minimum set of common transistors and resistors. They are not just a redundant set of drivers/receivers that are enabled or disabled. Because they are reconfigurable internally to the chip, the output pins for a driver/receiver are the same for RS232, RS422 and V.35. This (Image Omitted) eliminates the need for jumpers and/or different cables and connectors for RS232, RS422 and V.35.