Texas Instruments SN74AXCH4T245 4-Bit Bus Transceiver
Texas Instruments SN74AXCH4T245 4-Bit Bus Transceiver uses two individually configurable power-supply rails. The device is operational with VCCA and VCCB supplies as low as 0.65V. The A port is designed to track VCCA, which accepts any supply voltage from 0.65V to 3.6V. The B port is designed to track VCCB, which accepts any supply voltage from 0.65V to 3.6V. The Texas Instruments SN74AXCH4T245 is compatible with a single-supply system. The device is designed for asynchronous communication between data buses. It 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 (1DIR and 2DIR). The output-enable inputs (1OE and 2OE) disable the outputs so the buses are effectively isolated. All control pins (xDIR and xOE) are referenced to VCCA.Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Using pull-up or pull-down resistors with the bus-hold circuitry is not recommended. If a supply is present for VCCA or VCCB, the bus-hold circuitry always remains active on the A or B inputs, respectively, independent of the state of the direction control or output enable pins. The xOE pins should be tied to VCCA through a pull-up resistor to ensure the high-impedance state of the level shifter I/Os during power-up or power-down. This device is fully specified for partial-power-down applications using the Ioff current. The Ioff protection circuitry ensures that no excessive current is drawn from or sourced into input, output, or combined I/O that is biased to a specific voltage while the device is powered down.
Features
- Fully configurable dual-rail design allows each port to operate with a power supply range from 0.65V to 3.6V
- Bus-hold on data inputs eliminates the need for external pull-up or pull-down resistors
- Operating temperature from -40°C to +125°C
- Multiple direction control pins to allow simultaneous up and down translation
- Glitch-free power supply sequencing
- Up to 380Mbps support when translating from 1.8V to 3.3V
- VCC isolation feature
- Ioff supports partial-power-down mode operation
- Compatible with AVC family-level shifters
- Latch-up performance exceeds 100mA per JESD 78, Class II
- ESD protection exceeds JESD 22
- 8000V Human-body model
- 1000V Charged-device model
Applications
- Enterprise and communications
- Industrial
- Personal electronics
- Wireless infrastructure
- Building automation
Functional Block Diagram
