Texas Instruments SN74LV8T245PWR

Overview

SN74LV8T245PWR from Texas Instruments is an octal bus transceiver with 3-state outputs and integrated logic-level translation, supporting bidirectional voltage translation between 1.2 V and 5.5 V domains. It features DIR/OE dual-control logic, 5.5-V-tolerant inputs, and operates across 1.65 V–5.5 V VCC. Used in mixed-voltage I²C, SPI, and GPIO interconnects between microcontrollers and peripherals.

For engineers reviewing the SN74LV8T245PWR datasheet, SN74LV8T245PWR pinout, SN74LV8T245PWR application, or SN74LV8T245PWR equivalent, key selection criteria include verified up/down translation capability (e.g., 1.8 V ↔ 3.3 V), 3-state timing (t_Pd ≤ 11.5 ns @ 3.3 V), thermal performance in TSSOP-20 (R_θJA = 122.3°C/W), and latch-up immunity (>250 mA per JESD 17).

Technical Context

The SN74LV8T245PWR implements shared DIR/OE control for all eight channels, enabling simultaneous direction switching and global 3-state enable. Its LVxT-enhanced input structure provides reduced VIH/VIL thresholds for reliable up-translation (e.g., 1.2 V → 1.8 V) and 5.5-V-tolerant inputs for down-translation (e.g., 5 V → 2.5 V).

Output voltage levels are strictly referenced to VCC, supporting 1.8 V, 2.5 V, 3.3 V, and 5 V CMOS logic families. Propagation delay varies with supply: t_Pd = 4.5–11.5 ns (VCC = 5 V to 3.3 V, CL = 15 pF), and output drive strength scales with VCC (IOH = –8 mA @ 4.5 V, –5.5 mA @ 3.0 V).

Key Specifications

Pinout & Package

Packaged in PW (TSSOP-20) with 6.50 mm × 4.40 mm body size and wettable flanks for AOI-compatible solder joint inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV8T245PWR, SN74AVC8T245PW lacks 5 V input tolerance but offers superior speed at low voltage, while TXS0108EPWR eliminates DIR control at the cost of protocol-specific limitations and higher quiescent current - making SN74LV8T245PWR the most versatile choice for general-purpose mixed-voltage bus bridging.

Availability

SN74LV8T245PWR is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control, programmable logic I/O expansion, and industrial PLC backplane interface applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LV8T245PWR 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 leader specializing in analog, embedded processing, and logic solutions, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LV8T245PWR belongs to TI's LVxT logic family, engineered specifically for single-supply bidirectional level translation in space-constrained, mixed-voltage digital systems - targeting seamless interoperability between legacy and next-generation logic families.

FAQ

What voltage levels can SN74LV8T245PWR translate between?

SN74LV8T245PWR 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) across its full 1.65 V–5.5 V VCC range. Input tolerance up to 5.5 V enables direct connection of 5 V signals even when VCC = 1.8 V, and reduced VIH thresholds ensure reliable detection of sub-2 V inputs. All translations are bidirectional and controlled by the DIR pin.

Does SN74LV8T245PWR require external pull-up resistors on DIR or OE?

SN74LV8T245PWR does not require external pull-ups on DIR, but TI recommends tying OE to VCC via a 10-kΩ resistor to ensure outputs remain in high-impedance during power-up/power-down sequences. This prevents bus contention before firmware initializes the transceiver. The internal input leakage is ≤±1 µA, so 10 kΩ yields <10 mV offset - sufficient for noise margin while minimizing standby current.

What is the maximum data rate supported by SN74LV8T245PWR?

SN74LV8T245PWR supports up to 150 Mbps in 5 V systems (t_Pd = 4.5 ns min, CL = 15 pF) and maintains reliable operation at 100 Mbps in 3.3 V configurations (t_Pd = 6.4 ns min). Real-world throughput depends on load capacitance and signal integrity; TI validates performance up to 150 Mbps with CL ≤ 15 pF and proper PCB routing (controlled impedance, minimized stubs).

Can SN74LV8T245PWR replace SN74LVC8T245PWR in existing designs?

SN74LV8T245PWR is not a drop-in replacement for SN74LVC8T245PWR due to key differences: SN74LV8T245PWR has 5.5-V-tolerant inputs and LVxT-enhanced thresholds for level translation, while SN74LVC8T245PWR is a standard LVC device without translation capability. Swapping requires validation of input voltage compatibility and timing margins, especially if the original design relies on strict 3.3 V-only signaling.

How does thermal performance of SN74LV8T245PWR compare across packages?

SN74LV8T245PWR in PW (TSSOP-20) has R_θJA = 122.3°C/W, higher than RKS (VQFN, 67.7°C/W) or DGS (VSSOP, 118.4°C/W). In thermally constrained layouts, the TSSOP package requires careful copper pour and thermal vias under the pad. TI specifies junction-to-board (R_θJB) as 73.3°C/W for PW - meaning board-level heat spreading significantly impacts max allowable power dissipation.