Texas Instruments SN74LV245APWT

Overview

SN74LV245APWT from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for bidirectional asynchronous data transfer between voltage-domain-isolated buses. It operates from 2 V to 5.5 V, delivers ≤6.5 ns propagation delay at 5 V, supports mixed-mode I/O (e.g., 5 V inputs into 3.3 V system), and features Ioff partial-power-down protection. It is used in LED display column drivers where level-shifting and bus isolation prevent contention during power sequencing.

For engineers reviewing the SN74LV245APWT datasheet, SN74LV245APWT pinout, SN74LV245APWT application, or SN74LV245APWT equivalent, key selection criteria include its 20-pin TSSOP (PW) package, 35 mA per-output drive capability, ±1 µA control-input leakage, 3.3 V/5 V dual-voltage tolerance, and guaranteed 125°C operation - critical for industrial motor driver interface and telecom backplane buffer designs.

Technical Context

The SN74LV245APWT implements a direction-controlled, 8-bit bidirectional bus interface with independent output-enable (OE) logic. Its DIR input selects data flow direction (A→B or B→A), while OE places all outputs in high-impedance state for bus isolation. The device uses low-drive CMOS with intentionally slow edge rates to suppress output ringing on capacitive loads up to 50 pF.

It incorporates Ioff circuitry that disables outputs when VCC = 0 V, blocking current backflow during partial power-down. Inputs tolerate up to 5.5 V regardless of VCC, enabling robust down-translation (e.g., 5 V microcontroller to 3.3 V FPGA interface). Ground bounce (VOLP < 0.8 V) and VOH undershoot (VOHV > 2.3 V) are characterized at 3.3 V, confirming signal integrity in noise-sensitive applications.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 4.40 mm body, 0.65 mm pitch, exposed pad optional, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVC245A and SN74AVC245, the SN74LV245APWT uniquely combines 5.5 V input tolerance, Ioff protection, 125°C rating, and documented ground-bounce performance - making it the only option qualified for ruggedized industrial and telecom infrastructure where voltage domain bridging and thermal resilience are non-negotiable.

Availability

SN74LV245APWT is available at Aetrix Electronics and suitable for LED display driver interfaces, industrial motor control buses, and telecom backplane buffers requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for SN74LV245APWT 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 connectivity technologies with over 50 years of innovation in industrial, automotive, and communications markets.

The SN74LV245APWT belongs to TI's LV logic family, engineered for low-voltage, high-noise-immunity digital interfacing in harsh environments - specifically targeting applications demanding robust level translation, bus isolation, and extended temperature operation.

FAQ

What is the maximum operating temperature for SN74LV245APWT?

The SN74LV245APWT is fully specified from –40°C to +125°C ambient temperature. This rating is validated per JEDEC JESD22-A108 and applies across all recommended operating conditions, including 5.5 V supply and 16 mA output load. The TSSOP-20 package's thermal resistance (RθJA = 101.5°C/W) supports this rating with standard PCB copper pour.

Does SN74LV245APWT support 5 V to 3.3 V level translation?

Yes, the SN74LV245APWT supports bidirectional 5 V to 3.3 V level translation. Its inputs tolerate up to 5.5 V regardless of VCC, allowing 5 V signals to be safely driven into a 3.3 V-powered SN74LV245APWT. Outputs swing rail-to-rail (0 V to VCC), so a 3.3 V VCC yields 3.3 V logic-high levels compatible with 3.3 V receivers.

What is the purpose of the Ioff feature in SN74LV245APWT?

The Ioff feature in SN74LV245APWT disables all outputs when VCC = 0 V, preventing current backflow from live I/O pins into the unpowered device. This protects downstream circuitry during partial power-down scenarios - such as hot-plug insertion in telecom shelves or staged power sequencing in motor drives - and is verified per JEDEC JESD78.

Can SN74LV245APWT drive a 50 pF load at 10 MHz?

Yes, the SN74LV245APWT is characterized for 50 pF loads across its full voltage and temperature range. At VCC = 3.3 V and TA = 25°C, tpd is 11.9 ns and ten is 19 ns - well within timing budgets for 10 MHz (100 ns period) bus operation. Power dissipation capacitance (Cpd) is 20 pF at 3.3 V, confirming low dynamic power at this frequency.

How should OE and DIR be biased during power-up for reliable SN74LV245APWT operation?

For reliable power-up behavior, OE must be held high (via pull-up to VCC) and DIR set to the desired initial direction before VCC stabilizes. TI recommends a ≥10 kΩ pull-up on OE to ensure high-impedance state at power-on; DIR may be tied to GND or VCC depending on default data flow direction. Floating either pin risks bus contention or undefined output states.