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Qty Price
1-9 $3.44
10-24 $3.10
25-99 $2.89
100-249 $2.53
250-499 $2.37
500-749 $2.02
750-999 $1.70
1000+ $1.62


  • 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


Texas Instruments  SN74ALS640B-1NSR

These 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 () 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 IOL 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.