Texas Instruments SN74LV8T245DGSR

Overview

SN74LV8T245DGSR from Texas Instruments is an octal bus transceiver with 3-state outputs and integrated logic-level translation, operating from 1.65 V to 5.5 V supply. It supports bidirectional voltage translation (e.g., 1.8 V ↔ 3.3 V, 3.3 V ↔ 5.0 V), delivers ≤11 ns propagation delay at 5 V, features 5.5 V-tolerant inputs, and is qualified for industrial temperature range (–40°C to 125°C). It enables signal isolation between mixed-voltage domains in microcontroller I/O expansion interfaces.

For engineers reviewing the SN74LV8T245DGSR datasheet, SN74LV8T245DGSR pinout, SN74LV8T245DGSR application, or SN74LV8T245DGSR equivalent, key selection criteria include verified up/down translation capability across 1.2 V–5.5 V input ranges, guaranteed 3-state timing (ten/tdis ≤38 ns), thermal performance in VQFN-20 (RθJA = 67.7°C/W), and compatibility with 1.8-V/2.5-V/3.3-V/5-V CMOS logic families.

Technical Context

The SN74LV8T245DGSR implements dual-rail level shifting via a single-supply architecture where output logic levels are referenced solely to VCC, while inputs accept voltages up to 5.5 V independent of VCC. Its DIR and OE pins jointly control eight bidirectional channels, with functional modes defined by OE (active-low enable) and DIR (A→B or B→A direction).

It uses LVxT-enhanced input thresholds-VIH as low as 1.1 V at 1.65 V VCC-to support up-translation (e.g., 1.2 V input → 1.8 V output), and 5.5 V-tolerant inputs enable down-translation (e.g., 5.0 V input → 3.3 V output). All outputs are balanced CMOS with ±15 mA drive at 3.3 V/5 V and latch-up immunity exceeding 250 mA per JESD17.

Key Specifications

Pinout & Package

VQFN-20 (RKS) package: 4.50 mm × 2.50 mm body, 0.5 mm pitch, wettable flanks, exposed thermal pad (recommended to connect to GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVC8T245RHLR and TXS0108EPWR, the SN74LV8T245DGSR uniquely combines 5.5 V input tolerance, –40°C to 125°C operation, and explicit DIR/OE control-making it the only option among the three qualified for industrial and automotive mixed-voltage bus isolation with guaranteed timing margins.

Availability

SN74LV8T245DGSR is available at Aetrix Electronics and suitable for industrial sensor hubs, automotive body control modules, microcontroller I/O expansion, and automated test equipment requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for SN74LV8T245DGSR 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 specializing in analog and embedded processing technologies, with leadership in precision analog, power management, and logic solutions.

The SN74LV8T245DGSR belongs to TI's LVxT family of single-supply level translators, designed specifically for robust, pin-compatible interoperability between legacy and next-generation CMOS logic domains in industrial and automotive systems.

FAQ

What voltage levels can the SN74LV8T245DGSR translate between?

The SN74LV8T245DGSR supports verified up-translation (e.g., 1.2 V → 1.8 V, 1.8 V → 3.3 V) and down-translation (e.g., 5.0 V → 3.3 V, 3.3 V → 1.8 V) using a single VCC supply. Input tolerance up to 5.5 V enables connection to higher-voltage buses without external components, and output levels strictly follow VCC (1.65 V–5.5 V), making SN74LV8T245DGSR suitable for mixed-domain signal routing where precise rail referencing is required.

How does the DIR and OE pin configuration affect bus operation in the SN74LV8T245DGSR?

In the SN74LV8T245DGSR, DIR selects data direction (L = B→A, H = A→B) while OE (active low) globally enables/disables all outputs. When OE is high, all A and B ports enter high-impedance state regardless of DIR; when OE is low, only the selected port pair (A or B) drives based on DIR state. This dual-control scheme prevents bus contention during reset or power sequencing, and SN74LV8T245DGSR's function table guarantees that exactly one side is driven at any time-critical for shared-bus reliability.

Is the SN74LV8T245DGSR suitable for automotive applications?

Yes, the SN74LV8T245DGSR is qualified for operation from –40°C to 125°C and meets JESD17 latch-up immunity (>250 mA), making it suitable for automotive body control modules and infotainment interfaces. Its 5.5 V-tolerant inputs tolerate load-dump transients, and the VQFN-20 (RKS) package with wettable flanks supports AOI-based solder joint inspection-key for automotive manufacturing compliance. SN74LV8T245DGSR does not carry AEC-Q200 certification, so system-level validation is required per application.

What is the maximum data rate supported by the SN74LV8T245DGSR?

The SN74LV8T245DGSR supports up to 150 Mbps with 5 V or 3.3 V VCC, validated by switching characteristics showing tPD ≤5.3 ns (5 V, CL = 50 pF) and tsk(o) ≤1 ns. At 125°C, worst-case tPD remains ≤11 ns, allowing reliable operation at ≥50 MHz clock rates in SPI, parallel bus, or GPIO expansion applications. Signal integrity depends on proper termination and trace impedance matching-SN74LV8T245DGSR's balanced CMOS outputs minimize skew but require layout attention for >100 Mbps use.

Does the SN74LV8T245DGSR require external pull-up or pull-down resistors on unused pins?

Yes-per TI's design guidance, all unused inputs of the SN74LV8T245DGSR must be terminated to VCC or GND to prevent floating states that cause excessive ICC and potential oscillation. OE and DIR are particularly sensitive; OE should be pulled up to VCC via a 10-kΩ resistor to ensure high-impedance outputs at power-up. Unused A/B I/O pins may be left open only if permanently unconnected in the system, but tying them to VCC/GND is preferred for EMI and leakage control. SN74LV8T245DGSR's input leakage (±0.1 µA) makes 10-kΩ a safe default value.