SN74LVT245BNSR

This octal bus transceiver is designed specifically for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment. The SN74LVT245B 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 at the direction-control (DIR) input. The output-enable (OE) input can be used to disable the device so the buses are effectively isolated. To ensure the high-impedance state during power up or power down, OE(overline) should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. This device is fully specified for hot-insertion applications using I(off) and power-up 3-state. The I(0P) circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.

Applications

• Asynchronous communication between data buses
• Hot-plug applications

Key features

• Mixed-mode signal operation support; 5V I/O voltage compatible at 3.3V VCC
• Unregulated battery supply support; minimum operating voltage down to 2.7V
• Typical output ground bounce <0.8V at VCC=3.3V, TA=25℃
• Ioff and power-up 3-state features for hot insertion support
• Latch-up performance exceeds 100mA per JESD 78 Class II
• ESD protection exceeds JESD 22: 2000-V HBM (A114-A), 200-V MM (A115-A), 1000-V CDM (C101)
• Data transfer direction (A-to-B or B-to-A) controlled by DIR input logic level
• Device disabled via OE input for effective bus isolation
• To ensure high-impedance state during power-up/power-down, OE should be connected to VCC through a pull-up resistor; minimum resistance determined by driver sink current capability
• Ioff circuitry disables outputs when device is powered off, preventing destructive backflow current
• Power-up 3-state circuitry places outputs in high-impedance state during power-up and power-down to avoid drive conflicts
• Absolute maximum ratings: supply voltage -0.5V~4.6V, input voltage -0.5V~7V, output voltage in high-impedance or power-off state -0.5V~7V, output voltage in high state -0.5V~VCC+0.5V, output/input current in low state 128mA, output/input current in high state 64mA, output clamp current -50mA
• Thermal resistance by package: DB 70℃/W, DW 58℃/W, GQN/ZQN 78℃/W, NS 60℃/W, PW 83℃/W, RGY 37℃/W
• Storage temperature range: -65℃~150℃
• All unused inputs must be tied to VCC or GND for proper device operation