Product details

Number of channels 8 IOL (max) (mA) 24 IOH (max) (mA) -15 Input type TTL Output type TTL Features High speed (tpd 10-50ns), Over-voltage tolerant inputs Technology family ALS Rating Catalog Operating temperature range (°C) 0 to 70
Number of channels 8 IOL (max) (mA) 24 IOH (max) (mA) -15 Input type TTL Output type TTL Features High speed (tpd 10-50ns), Over-voltage tolerant inputs Technology family ALS Rating Catalog Operating temperature range (°C) 0 to 70
PDIP (N) 20 228.702 mm² (24.33 mm × 9.4 mm) SOIC (DW) 20 131.84 mm² (12.8 mm × 10.3 mm)
  • Bidirectional Bus Transceivers in High-Density 20-Pin Packages
  • Choice of True or Inverting Logic
  • A-Bus Outputs Are Open Collector; B-Bus Outputs Are 3 State
  • Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs

 

  • Bidirectional Bus Transceivers in High-Density 20-Pin Packages
  • Choice of True or Inverting Logic
  • A-Bus Outputs Are Open Collector; B-Bus Outputs Are 3 State
  • Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs

 

These octal bus transceivers are designed for asynchronous two-way communication 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 () 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 recommended maximum IOL is increased to 48 mA.

The SN74ALS638A, SN74ALS639A, SN74AS638A, and SN74AS639 are characterized for operation from 0°C to 70°C.

 

 

These octal bus transceivers are designed for asynchronous two-way communication 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 () 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 recommended maximum IOL is increased to 48 mA.

The SN74ALS638A, SN74ALS639A, SN74AS638A, and SN74AS639 are characterized for operation from 0°C to 70°C.

 

 

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* Data sheet Octal Bus Transceivers datasheet (Rev. A) Jan 1, 1995

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