Texas Instruments SN74ALVC245DGVR

Overview

SN74ALVC245DGVR from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between 1.65-V to 3.6-V buses. It features ±24-mA drive strength at 3.3 V, 3.4-ns max propagation delay, and operates across –40°C to 85°C. Used in level-shifting interfaces between mixed-voltage subsystems in industrial control and embedded communications.

For engineers reviewing the SN74ALVC245DGVR datasheet, SN74ALVC245DGVR pinout, SN74ALVC245DGVR application, or SN74ALVC245DGVR equivalent, key selection criteria include direction-control logic behavior, 3-state isolation timing (ten/tdis), supply voltage compatibility, thermal impedance (θ_JA = 92°C/W), and TVSOP-20 package footprint constraints.

Technical Context

The SN74ALVC245DGVR implements dual-bus bidirectional data routing controlled by DIR (direction) and OE (output enable) inputs. Its CMOS ALVC logic family ensures rail-to-rail input thresholds scaled to V_CC, supporting interoperability across 1.65–3.6 V domains without external level shifters.

Each of the eight A/B channel pairs supports independent 3-state output control via OE, while DIR determines signal flow direction (A→B or B→A). Latch-up immunity exceeds 250 mA per JESD 17, and I/O pins tolerate –0.5 V to V_CC + 0.5 V, enabling hot-swap capability in backplane applications.

Key Specifications

Pinout & Package

SN74ALVC245DGVR uses a 20-pin Thin Very Small Outline Package (TVSOP, DGV), 4.4 mm × 6.5 mm body size, 0.5-mm lead pitch, 1.2-mm max height, with gull-wing leads and exposed pad not present (non-thermal-pad variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bus transceiver applications.

Compared with SN74ALVC245DGVR, SN74LVC245APW offers tighter thermal performance but weaker latch-up immunity, while 74AVC245TTR extends voltage range downward at the cost of propagation delay-making SN74ALVC245DGVR optimal for industrial-grade 1.65–3.6 V bidirectional interfacing requiring robust fault tolerance.

Availability

SN74ALVC245DGVR is available at Aetrix Electronics and suitable for industrial PLC backplanes, FPGA-to-microcontroller bridges, automotive infotainment links, and automated test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74ALVC245DGVR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The SN74ALVC245DGVR belongs to TI's ALVC (Advanced Low-Voltage CMOS) logic family, engineered specifically for high-speed, low-voltage bidirectional bus interfacing in mixed-supply systems where reliability, timing precision, and latch-up immunity are critical.

FAQ

What is the recommended power-up sequence for SN74ALVC245DGVR to ensure high-impedance outputs?

TI recommends tying OE to V_CC through a pullup resistor during power-up to guarantee high-impedance outputs before logic stabilization. For SN74ALVC245DGVR, a 10-kΩ resistor suffices given its ±5-µA input leakage at 3.6 V. This prevents bus contention if A/B-side drivers power up before the transceiver, and aligns with the device's requirement for OE to be HIGH before V_CC reaches 1.5 V.

Does SN74ALVC245DGVR support hot-swap insertion into a live backplane?

Yes, SN74ALVC245DGVR supports hot-swap operation due to its I/O voltage tolerance of –0.5 V to V_CC + 0.5 V and latch-up immunity exceeding 250 mA per JESD 17. When inserted into a powered backplane, the device withstands transient voltage differentials between its pins and local ground, provided OE remains HIGH until V_CC stabilizes. No external protection circuitry is required for typical 3.3-V backplane applications.

Can SN74ALVC245DGVR operate reliably at 1.65 V supply with full timing specifications?

Yes, SN74ALVC245DGVR is fully specified down to 1.65 V: t_pd ≤ 6 ns, t_en ≤ 8.6 ns, and t_dis ≤ 8 ns at 1.65 V and 25°C. Input thresholds scale to V_CC, so V_IH = 0.65 × V_CC (≈1.07 V) and V_IL = 0.35 × V_CC (≈0.58 V), ensuring noise margins >300 mV. All DC parameters-including ±4-mA output drive-are guaranteed across the full 1.65–3.6 V range.

What is the maximum capacitive load SN74ALVC245DGVR can drive while maintaining 3.4-ns propagation delay?

The 3.4-ns max t_pd for SN74ALVC245DGVR is characterized at CL = 30 pF (for V_CC = 3.3 V). Driving loads >50 pF increases t_pd nonlinearly-TI's switching characteristics table shows t_pd = 6 ns at CL = 50 pF. For designs requiring ≤3.4 ns, keep total net capacitance (including trace, probe, and receiver input) ≤30 pF using short traces (<2 cm) and low-C_in receivers (e.g., TI's LVC-series inputs at 4.5 pF).

How does the DIR pin behavior affect bus contention risk in SN74ALVC245DGVR?

Bus contention in SN74ALVC245DGVR occurs only if DIR changes while OE is LOW and both A and B buses are actively driven. The device has no internal arbitration; DIR is purely combinatorial. To eliminate risk, TI mandates that DIR be stabilized ≥1 ns before OE goes LOW (per setup time t_su in timing diagrams), and that OE remain HIGH during DIR transitions. Violating this causes momentary dual-driver activation on one or more lines, potentially exceeding ±50-mA absolute max output current.