Texas Instruments SN74LVCH245APWTG4

Overview

SN74LVCH245APWTG4 from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for bidirectional data flow between 1.65-V to 3.6-V buses while accepting 5.5-V-tolerant inputs. It features direction control (DIR), active-low output enable (OE), bus-hold on all data I/Os, Ioff live-insertion support, and 6.3 ns max propagation delay at 3.3 V - enabling use in mixed-voltage server backplanes and embedded interconnects.

For engineers reviewing the SN74LVCH245APWTG4 datasheet, SN74LVCH245APWTG4 pinout, SN74LVCH245APWTG4 application, or SN74LVCH245APWTG4 equivalent, key selection criteria include its 5.5-V input tolerance across 1.65–3.6-V VCC operation, guaranteed tpd ≤6.3 ns at 3.3 V, Ioff-enabled partial-power-down capability, bus-hold elimination of external resistors, and thermal performance in TSSOP-20 package.

Technical Context

This device implements asynchronous bidirectional data translation via a DIR-controlled signal path between two 8-bit parallel buses (A and B ports), with OE gating all outputs into high-impedance state. Its CMOS input structure supports 5.5-V logic levels independent of VCC, enabling interoperability between 3.3-V and 5-V subsystems without level-shifting components.

The integrated bus-hold circuit maintains valid logic states on floating A/B port inputs without external biasing, while Ioff protection limits reverse current during power sequencing. Output drive strength is balanced (±24 mA at 3 V), and switching characteristics are characterized from –40°C to 125°C with CL = 50 pF loads.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 4.40 mm body, 0.65 mm lead pitch, surface-mount, moisture-sensitive level 1 (MSL-1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245A and SN74AVC245, SN74LVCH245APWTG4 uniquely combines 5.5-V input tolerance, bus-hold, and Ioff in a single TSSOP-20 package - making it the only option among the three that supports unmodified 5-V-to-3.3-V translation with live-insertion safety and zero external bias components.

Availability

SN74LVCH245APWTG4 is available at Aetrix Electronics and suitable for server backplanes, industrial PLC I/O modules, wearable health sensor hubs, and telecom line card interfaces requiring stable component supply across extended temperature and mixed-voltage operating conditions.

Supply support for SN74LVCH245APWTG4 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 delivering analog and embedded processing solutions, with over 90 years of innovation in precision analog, power management, and logic ICs.

SN74LVCH245APWTG4 belongs to TI's LVCH logic family - engineered for robust mixed-signal interfacing in industrial, computing, and communications equipment where voltage translation, power sequencing resilience, and board-level integration efficiency are critical.

FAQ

What is the maximum input voltage rating for SN74LVCH245APWTG4?

The SN74LVCH245APWTG4 supports input voltages up to 5.5 V across all A and B port pins, regardless of VCC level (1.65–3.6 V). This allows direct connection to 5-V logic sources without external level-shifting circuitry, simplifying design in mixed-voltage systems and reducing component count. The specification is validated per Absolute Maximum Ratings in the official datasheet SCES008Q.

Does SN74LVCH245APWTG4 require external pullup or pulldown resistors on its data lines?

No - SN74LVCH245APWTG4 integrates bus-hold circuitry on all A and B port inputs, actively maintaining valid logic states on floating lines. This eliminates the need for external pullup or pulldown resistors, reducing BOM cost, PCB area, and potential signal integrity issues from resistor parasitics. Bus-hold remains active regardless of OE or DIR state.

Can SN74LVCH245APWTG4 be used in hot-swap applications?

Yes - SN74LVCH245APWTG4 includes Ioff circuitry that disables outputs and limits reverse current when VCC = 0 V, enabling safe live insertion into powered-backplane systems. This feature is explicitly validated per JEDEC JESD78 and supports reliable operation in modular server, telecom, and industrial chassis where field-replaceable units are inserted under power.

What is the propagation delay of SN74LVCH245APWTG4 at 3.3 V?

At VCC = 3.3 V and TA = 25°C, the maximum propagation delay (tpd) of SN74LVCH245APWTG4 is 6.3 ns for A↔B data paths, as specified in the Switching Characteristics table (Section 6.8) of datasheet SCES008Q. This value is guaranteed across –40°C to +125°C when loaded with CL = 50 pF, supporting timing-critical applications such as memory-mapped I/O and high-speed peripheral bridging.

Which package type does SN74LVCH245APWTG4 use?

SN74LVCH245APWTG4 uses the TSSOP-20 (PW) package: 6.50 mm × 4.40 mm body size, 0.65 mm lead pitch, surface-mount, RoHS-compliant, and moisture-sensitive level 1 (MSL-1). This compact, thermally efficient package supports automated assembly and delivers RθJA = 102.5°C/W - suitable for dense PCB layouts in space-constrained embedded systems.