CY54FCT646T - Octal Registered Bus Transceivers with 3-State Outputs

The \x92FCT646T devices consist of a bus transceiver circuit with 3-state, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal registers. Data on the A or B bus is clocked into the registers as the appropriate clock pin goes to a high logic level. Output-enable (G\) and direction (DIR) inputs control the transceiver function. In the transceiver mode,data present at the high-impedance port can be stored in either the A or B register, or in both. Select controls (SAB, SBA) can multiplex stored and real-time (transparent mode) data. DIR determines which bus receives data when G\ is low. In the isolation mode (G\ is high), A data can be stored in the B register and/or B data can be stored in the A register.

These devices are fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

• Function, Pinout, and Drive Compatible With FCT and F Logic
• Reduced V_OH (Typically = 3.3 V) Versions of Equivalent FCT Functions
• Edge-Rate Control Circuitry for Significantly Improved Noise Characteristics
• I_off Supports Partial-Power-Down Mode Operation
• Matched Rise and Fall Times
• Fully Compatible With TTL Input and Output Logic Levels
• ESD Protection Exceeds JESD 22
  • 2000-V Human-Body Model (A114-A)
  • 200-V Machine Model (A115-A)
  • 1000-V Charged-Device Model (C101)
• Independent Register for A and B Buses
• CY54FCT646T
  • 48-mA Output Sink Current
  • 12-mA Output Source Current
• CY74FCT646T
  • 64-mA Output Sink Current
  • 32-mA Output Source Current
• 3-State Outputs