Four channel unidirectional level shifter

TXU0104 / TXUN0104 is

a 4-bit, dual-supply noninverting fixed direction voltage level translation device.

Ax pins are referenced to VCCA logic level, OE pin can be referenced to

either VCCA or VCCB logic levels, and Bx pins are referenced

to VCCB logic levels. The A port is able to accept input voltages ranging

from 1.1V to 5.5V, while the B port can also accept input voltages from 1.1V to

5.5V. Fixed direction data transmission can occur from A to B or B to A when OE is

set to high in reference to either supply. When OE is set to low, all output pins

are in the high-impedance state. The only difference between TXU0104 and TXUN0104 is

the OE / OE signal being active high and active low

respectively. See for a summary of the operation of the control logic.