SN74AS640

• Bidirectional Bus Transceivers in High-Density 20-Pin Packages
• Inverting Logic
• Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs

Supply voltage, V_CC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 7 V
Input voltage, V_I: All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, T_A: SN54ALS640B . . . 55°C to 125°C
                                                                   SN74ALS640B . . . . . . . 0°C to 70°C
Storage temperature range . . . . . . . . . . . . . . . . . . . .. . . . . . . 65°C to 150°C
‡ Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

These SN74ALS640B and SN74AS640 octal bus transceivers are designed for asynchronous two-way communication between data buses. These devices transmit data from the A bus to the B bus or from the B bus to the A bus, depending upon the level at the direction-control (DIR) input. The output-enable (OE) input can be used to disable the device so that the buses are effectively isolated.The -1 version of the SN74ALS640B is identical to the standard version, except that the recommended maximum I_OL for the -1 version is increased to 48 mA. There is no -1 version of the SN54ALS640B.

The SN54ALS640B and SN54AS640 are characterized for operation over the full military temperature range of 55°C to 125°C. The SN74ALS640B and SN74AS640 are characterized for operation from 0°C to 70°C.