SN74AS639 Datasheet | Texas Instruments

description These octal bus transceivers are designed for asynchronous two-way munication between open-collector and 3-state buses. The devices transmit data from the A bus (open-collector) to the B bus (3 state) or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The output-enable (OE) input can be used to disable the device so the buses are isolated. The -1 version of SN74ALS638A is identical to the standard version, except that the remended maximum IOL is increased to 48 m A. The SN74ALS638A, SN74ALS639A, SN74AS638A, and SN74AS639 are characterized for operation from 0°C to 70°C. INPUTS OE DIR FUNCTION TABLE OPERATION SN74ALS638A SN74AS638A SN74ALS639A SN74AS639 B data to A bus B data to A bus A data to B bus A data to B bus Isolation Isolation PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. - POST OFFICE BOX 655303 DALLAS, TEXAS 75265 Copyright © 1995, Texas Instruments Incorporated 1 SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639 OCTAL BUS TRANSCEIVERS SDAS123A - DECEMBER 1983 - REVISED JANUARY 1995 logic symbols† 19 OE 1 DIR SN74ALS638A, SN74AS638A G3 3 EN1 [BA] 3 EN2 [AB] 2 A1 3 A2 4 A3 5 A4 6 A5 7 A6 8 A7 9 A8 1...