具有可配置电压转换和三态输出的增强型产品 8 位双电源总线收发器 24-SOIC -55 to 125
This 8-bit noninverting bus transceiver uses two separate configurable power-supply rails. The SN74LVC8T245-EP is optimized to operate with VCCA and VCCB set at 1.65 V to 5.5 V. The A port is designed to track VCCA. VCCA accepts any supply voltage from 1.65 V to 5.5 V. The B port is designed to track VCCB. VCCB accepts any supply voltage from 1.65 V to 5.5 V. This allows for universal low-voltage bidirectional translation between any of the 1.8-V, 2.5-V, 3.3-V, and 5.5-V voltage nodes.
The SN74LVC8T245-EP is designed for asynchronous communication between two data buses. The logic levels of the direction-control DIR input and the output-enable OE input activate either the B-port outputs or the A-port outputs or place both output ports into the high-impedance mode. The device transmits data from the A bus to the B bus when the B-port outputs are activated, and from the B bus to the A bus when the A-port outputs are activated. The input circuitry on both A and B ports is always active and must have a logic HIGH or LOW level applied to prevent excess ICC and ICCZ.
The SN74LVC8T245-EP is designed so that the control pins DIR and OE are supplied by VCCA.
This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.
The VCC isolation feature ensures that if either VCC input is at GND, all outputs are in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE 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.
