SN74LVC245APWR

Buffers, Drivers, Receivers, Transceivers Overview

The SN74LVC245A is an octal bus transceiver with 3-state outputs designed for 1.65-V to 3.6-V VCC operation. It facilitates asynchronous communication between data buses, transmitting data from the A bus to the B bus or vice versa based on the DIR input logic level. The device supports mixed-mode signal operation, allowing inputs to accept voltages up to 5.5 V while operating at lower supply voltages. Key electrical characteristics include a maximum propagation delay of 6.3 ns at 3.3 V and typical output ground bounce of 2 V. It features Ioff support for live insertion and partial-power-down modes, ensuring no back drive current when powered down.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Supports bidirectional data transmission between two 8-bit buses with direction control via the DIR pin.
• Enables mixed-voltage system integration by accepting 5.5 V input signals while operating at supply voltages as low as 1.65 V.
• Provides high-impedance isolation when the OE pin is high, preventing bus contention during power-up or power-down cycles.
• Includes built-in circuitry to disable outputs during partial-power-down states, protecting against damaging back drive currents.

Buffers, Drivers, Receivers, Transceivers Applications

• Cable modem termination systems
• Servers
• LED displays
• Network switches
• I/O expanders

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific package variant (e.g., PW, DB, DW) required for your PCB layout, as the SN74LVC245A family includes multiple physical packages such as TSSOP, SSOP, SOIC, and VQFN. Confirm that the ordering suffix matches the desired tape-and-reel or tube quantity. Ensure the selected part meets the -40°C to 125°C operating temperature range specified in the datasheet. Cross-reference the manufacturer's latest orderable addendum for current availability and RoHS compliance status before finalizing procurement.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when designing systems requiring voltage translation between 5-V and 3.3-V or 1.8-V domains. It is suitable for applications needing high drive capability and fast switching speeds, such as network switches or server interfaces. Consider the thermal resistance metrics if operating in high ambient temperatures or enclosed spaces. Ensure unused inputs are tied to VCC or GND to prevent undefined operational states and excessive power consumption.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to Texas Instruments' LVC (Low Voltage CMOS) family, which is optimized for low-power applications across a wide supply voltage range. The SN74LVC245A serves as a standard interface solution for connecting microcontrollers, memory devices, and other digital logic components operating at different voltage levels. Its octal configuration allows for efficient parallel data transfer, making it a fundamental building block in modern digital bus architectures.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

Check for direct pin-compatible alternatives within the same LVC family, such as the SN74LVC245ADBRE4 or SN74LVC245APWRE4, which may offer updated manufacturing processes or packaging options. Verify that any substitute maintains the same 5.5-V input tolerance and 3-state output characteristics. Ensure the replacement part supports the required operating temperature range and ESD protection levels specified in the original design.

Buffers, Drivers, Receivers, Transceivers FAQ

How does the SN74LVC245A handle mixed-mode signal operation?

The device allows inputs to accept voltages up to 5.5 V regardless of the VCC supply voltage, enabling safe interfacing between 5-V logic sources and 3.3-V or 1.8-V powered destinations without external level shifters.

What is the function of the Ioff feature?

The Ioff circuitry automatically disables the outputs when the device is powered down, preventing damaging current from flowing back through the device into the power rails, which supports live insertion and partial-power-down applications.

How is the data direction controlled?

Data flow is determined by the DIR input pin. When DIR is high, data propagates from the A bus to the B bus. When DIR is low, data flows from the B bus to the A bus.