Texas Instruments SN74LVC245APWRE4

Overview

SN74LVC245APWRE4 from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for bidirectional asynchronous data transfer between 1.65-V to 3.6-V buses. It supports mixed-mode I/O (5.5-V-tolerant inputs at 3.3-V VCC), delivers ≤6.3 ns propagation delay at 3.3 V, and features Ioff for live insertion and partial-power-down protection - used in server backplanes and LED display controllers.

For engineers reviewing the SN74LVC245APWRE4 datasheet, SN74LVC245APWRE4 pinout, SN74LVC245APWRE4 application, or SN74LVC245APWRE4 equivalent, key selection criteria include voltage translation capability (5 V ↔ 3.3 V), 3-state output isolation timing (ten/tdis ≤8.5 ns), thermal performance in TSSOP-20 (RθJA = 83.6°C/W), and Ioff-enabled back-drive protection during power sequencing.

Technical Context

The SN74LVC245APWRE4 implements a dual-bus directional control architecture using DIR (direction) and OE (output enable) inputs. Its CMOS design enables true bidirectional signal flow: when OE is low, data propagates A→B if DIR = high, or B→A if DIR = low; when OE is high, all outputs enter high-impedance state regardless of DIR.

It integrates overvoltage-tolerant input buffers (VI up to 5.5 V), rail-to-rail output swing (VOH ≥ VCC – 0.2 V, VOL ≤ 0.6 V at 3.3 V), and robust ESD protection (2000-V HBM, 1000-V CDM). The device meets JESD 17 latch-up immunity (>250 mA) and operates across –40°C to +125°C.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.50 mm × 4.40 mm body size, 0.65-mm lead pitch, RoHS-compliant NiPdAu finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245APWR, SN74LVC245APWRE4 offers identical performance but with TI's E4-compliant traceability; versus 74LVC245ADTR, it provides verified Ioff, faster timing, and superior thermal resistance - critical for high-reliability embedded designs.

Availability

SN74LVC245APWRE4 is available at Aetrix Electronics and suitable for server backplanes, LED display controllers, industrial motor drives, telecom line cards, and I/O expander modules requiring stable component supply across extended temperature ranges.

Supply support for SN74LVC245APWRE4 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 SN74LVC245A product line delivers robust, low-voltage CMOS bus transceivers optimized for mixed-signal interfacing, voltage translation, and hot-pluggable system architectures - targeting high-density, thermally constrained applications.

FAQ

What is the maximum operating voltage for inputs on the SN74LVC245APWRE4?

The SN74LVC245APWRE4 accepts input voltages up to 5.5 V across its entire valid VCC range (1.65 V to 3.6 V), enabling direct interfacing with 5-V logic while powered from 3.3-V or lower supplies. This overvoltage tolerance is specified in the Recommended Operating Conditions table and applies to all A- and B-side I/O pins, not just control inputs.

Does the SN74LVC245APWRE4 support hot-swap functionality?

Yes, the SN74LVC245APWRE4 supports hot-swap via its Ioff feature, which disables all outputs when VCC = 0 V, preventing current backflow from live buses into the unpowered device. This behavior is validated per JESD 78 and explicitly documented in Section 9.3 of the datasheet, making SN74LVC245APWRE4 suitable for modular server and telecom chassis designs.

What is the propagation delay of the SN74LVC245APWRE4 at 3.3 V?

The SN74LVC245APWRE4 has a maximum propagation delay (tpd) of 6.3 ns at VCC = 3.3 V ± 0.3 V, measured under standard load conditions (CL = 50 pF, TA = 25°C). This value is confirmed in Table 7.6 (Switching Characteristics) and enables reliable operation in systems requiring sub-10-ns timing margins, such as high-speed memory interfaces and real-time control loops.

Can the SN74LVC245APWRE4 be used for level translation between 5-V and 1.8-V systems?

Yes, the SN74LVC245APWRE4 supports down-translation from 5-V inputs to 1.8-V outputs when VCC = 1.8 V, as confirmed in Section 9.3 ("Feature Description") and Table 7.3 (Recommended Operating Conditions). Input thresholds scale with VCC, and output VOH/VOL remain compatible with 1.8-V logic families - verified across –40°C to +125°C.

What package type is used for the SN74LVC245APWRE4?

The SN74LVC245APWRE4 uses a 20-pin TSSOP (Thin Shrink Small Outline Package) with 6.50 mm × 4.40 mm body dimensions and 0.65-mm lead pitch. It is RoHS-compliant, has NiPdAu lead finish, and carries MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH), as specified in the Package Option Addendum.