The ST75185 contains three drivers and five receivers. The pinout matches the DB9Sconnector design in order to decrease the partcount, reduce the board space required and alloweasy interconnection of the UART and serial portconnector of IBM PC/ATTM and compatibles. Thebipolar circuits and processing of the ST75185provides a rugged low-cost solution for thisfunction at the expense of quiescent power andexternal passive components relative to theST75C185.The ST75185 complies with the requirements ofthe EIA/TIA 232-E and ITU (formally CCITT) v.28standards. These standards are for datainterchange between a host computer andperipheral at signalling rates up to 20k-bits/s. Theswitching speeds of the ST75185 are fast enoughto support rates up to 120K-bits/s with lowercapacitive loads (shorter cables). Interoperabilityat the higher signalling rates cannot be assuredunless the designer has design control of thecable and the interface circuits at the both ends.For interoperability at signalling rates to 120K-bits/s, use of EIA/ITA-423-B (ITU v.10) and EIA/ITA-422-B (ITU v.11) standards arerecommended.The ST75185 is characterized for operation overthe range of 0°C to 70°C.