The 74AVC series of bus transceivers support level-up and level-down voltage translation from either of their dual power supplies in bidirectional communication systems using signal voltages between 0.8V and 3.6V.
To support direct level-shifting of UART data, the 74AVC4T245FT includes four bidirectional level shift circuits, which allow independent control of the signal direction every 2 bits. The 74AVCH4T245FT also delivers this functionality but additionally includes a built-in bus-hold function that allows it to retain its previous output even when the input is in a high-impedance state. The 74AVC4T345FT offers 3-bit and 1-bit communications control, making it suitable for use with SPI interfaces.
The output stage of these transceivers can be placed in a high impedance state by either connecting one of the power supplies or the OE terminal input to GND, while signal direction is determined using the DIR pin.
To simplify power management, particularly in legacy system designs, these devices have been designed without any restrictions on the on/off sequencing of power supply terminals VCCA and VCCB. Furthermore, low static current consumption (ICCA, ICCB = 8μA (max.)) helps to save power.
The transceivers, which are housed in a TSSOP16B package, can reliably operate in temperatures ranging from -40°C to 125°C.
