SN74AVC4T245 - 4-Bit Dual-Supply Bus Transceiver with Configurable Voltage-Level Shifting and 3-State Outputs

This 4-bit noninverting bus transceiver uses two separate configurable power-supply rails. The A port is designed to track V_CCA. V_CCA accepts any supply 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. The SN74AVC4T245 is optimized to operate with V_CCA/V_CCB set at 1.4 V to 3.6 V. It is operational with V_CCA/V_CCB as low as 1.2 V. This allows for universal low-voltage bidirectional translation between any of the 1.2-V, 1.5-V, 1.8-V, 2.5-V, and 3.3-V voltage nodes.

The SN74AVC4T245 device is designed for asynchronous communication between two data buses. The logic levels of the direction-control (DIR) input and the output-enable (OE) input activate either the B-port outputs or the A-port outputs or place both output ports into the high-impedance mode. The device transmits data from the A bus to the B bus when the B-port outputs are activated, and from the B bus to the A bus when the A-port outputs are activated. The input circuitry on both A and B ports is always active and must have a logic HIGH or LOW level applied to prevent excess I_CC and I_CCZ.

The SN74AVC4T245 device is designed so that the control pins (1DIR, 2DIR, 1OE, and 2OE) are supplied by V_CCA.

This device is 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.

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

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

• Control Inputs V_IH/V_IL Levels Are
  Referenced to V_CCA Voltage
• Fully Configurable Dual-Rail Design Allows Each Port to Operate
  Over the Full 1.2-V to 3.6-V Power-Supply Range
• I/Os Are 4.6-V Tolerant
• I_off Supports Partial Power-Down-Mode Operation
• Maximum Data Rates
  • 380 Mbps (1.8-V to 3.3-V Translation)
  • 200 Mbps (< 1.8-V to 3.3-V Translation)
  • 200 Mbps (Translate to 2.5 V or 1.8 V)
  • 150 Mbps (Translate to 1.5 V)
  • 100 Mbps (Translate to 1.2 V)
• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
• ESD Protection Exceeds JESD 22
  • 8000-V Human-Body Model (A114-A)
  • 150-V Machine Model (A115-A)
  • 1000-V Charged-Device Model (C101)