SN74AVC8T245 - 8-Bit Dual-Supply Bus Transceiver with Configurable Voltage-Level Shifting and 3-State Outputs

This 8-bit noninverting bus transceiver uses two separate configurable power-supplyrails. The SN74AVC8T245 is optimized to operate withV_CCA/V_CCB set at 1.4 V to 3.6 V. The device isoperational with V_CCA/V_CCB as low as 1.2 V. The Aport is designed to track V_CCA. V_CCA accepts anysupply voltage from 1.2 V to 3.6 V. The B port is designed to track V_CCB.V_CCB accepts any supply voltage from 1.2 V to 3.6 V. This allows foruniversal low-voltage bidirectional translation between any of the 1.2-V, 1.5-V, 1.8-V, 2.5-V, and3.3-V voltage nodes.

The SN74AVC8T245 is designed for asynchronous communication between data buses. Thedevice transmits data from the A bus to the B bus or from the B bus to the A bus, depending on thelogic level at the direction-control (DIR) input. The output-enable (OE)input can be used to disable the outputs so the buses are effectively isolated.

The SN74AVC8T245 is designed so that the control pins (DIR and OE)are supplied by V_CCA.

The SN74AVC8T245 solution is compatible with a single-supply system and can be replacedlater with a ’245 function, with minimal printed circuit board redesign.

This device is fully specified for partial-power-down applications usingI_off. The I_off circuitry disables the outputs, thuspreventing damaging current backflow through the device when it is powered down.

The V_CC isolation feature ensures that if eitherV_CC input is at GND, both ports are in the high-impedance state.

To ensure the high-impedance state during power up or power down,OE shall be tied to V_CC through a pullup resistor;the minimum value of the resistor is determined by the current-sinking capability of thedriver.

• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
• ESD Protection Exceeds JESD 22
  • 8000-V Human-Body Model (A114-A)
  • 200-V Machine Model (A115-A)
  • 1000-V Charged-Device Model (C101)
• Control Inputs V_IH/V_IL Levels Are Referenced to V_CCA Voltage
• V_CC Isolation Feature – If Either V_CC Input Is at GND, All I/O Ports Are in the High-Impedance State
• I_off Supports Partial Power-Down Mode Operation
• Fully Configurable Dual-Rail Design Allows Each Port to Operate Over the Full 1.4-V to 3.6-V Power-Supply Range
• I/Os Are 4.6-V Tolerant
• Maximum Data Rates
  • 170 Mbps (V_CCA  < 1.8 V or V_CCB  < 1.8 V)
  • 320 Mbps (V_CCA  ≥ 1.8 V and V_CCB  ≥ 1.8 V)

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