Radiation-tolerant, eight-bit, 0.65-V to 3.3-V, direction-controlled level translator

The SN54SLC8T245-SEP device is an 8-bit non-inverting bus transceiver that resolves voltage level mismatch between devices operating at the latest voltage nodes (0.7 V, 0.8 V, and 0.9 V) and devices operating at industry standard voltage nodes (1.8 V, 2.5 V, and 3.3 V).

The device operates by using two independent power-supply rails (V CCA and V CCB) that operate as low as 0.65 V. Data pins A1 through A8 are designed to track V CCA, which accepts any supply voltage from 0.65 V to 3.6 V. Data pins B1 through B8 are designed to track V CCB, which accepts any supply voltage from 0.65 V to 3.6 V.

The SN54SLC8T245-SEP device is designed for 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 of the direction-control inputs (DIR1 and DIR2). The output-enable ( OE) input is used to disable the outputs so the buses are effectively isolated.

The SN54SLC8T245-SEP device is designed so the control pins (DIR and OE) are referenced to V CCA.

This device is fully specified for 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 is designed so that if either V CC input supply is below 100 mV, all level shifter outputs are disabled and placed into a high-impedance state.

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