Automotive Catalog 8-Bit Dual-Supply Bus Transceiver w/ Configurable Voltage Transl., 3-State Output

The SN74AVC8T245-Q1 is an 8-bit noninverting bus transceiver that uses two separate configurable power-supply rails. The SN74AVC8T245-Q1 operation is optimal with V CCA and V CCB set at 1.4 V to 3.6 V. It is operational with V CCA and V CCB as low as 1.2 V. 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. 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 SN74AVC8T245-Q1 design enables asynchronous communication between data buses. The device transmits data from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. One can use the output-enable ( OE) input to disable the outputs so the buses are effectively isolated.

In the SN74AVC8T245-Q1 design, V CCA supplies the control pins (DIR and OE).

This device specification covers partial-power-down applications using I off. The I off circuitry disables the outputs when the device is powered down. This inhibits current backflow into the device which prevents damage to the device.

The V CC isolation feature allows both ports to be in the high-impedance state if either V CC input is at GND.

To put the device in the high-impedance state during power up or power down, tie OE to V CC through a pullup resistor; the current-sinking capability of the driver determines the minimum value of the resistor.