STMicroelectronics 74LCXH16245TTR

Overview

74LCXH16245TTR from STMicroelectronics is a low-voltage CMOS 16-bit bus transceiver (3-state) with 5V-tolerant I/O, operating at 2.0–3.6 V supply, delivering 4.5 ns max propagation delay at VCC = 3 V, ±24 mA output drive, and bus-hold on all data terminals - used for bidirectional asynchronous data bus interfacing between 3.3 V logic domains and legacy 5 V systems.

For engineers reviewing the 74LCXH16245TTR datasheet, 74LCXH16245TTR pinout, 74LCXH16245TTR application, or 74LCXH16245TTR equivalent, key selection considerations include 5V-tolerant I/O compatibility, symmetrical 24 mA drive strength, bus-hold functionality eliminating external resistors, high-speed 3.3 V operation with AC/ACT-equivalent timing, and TSSOP-48 package constraints for dense PCB layouts.

Technical Context

This transceiver implements dual 8-bit bidirectional data paths controlled by independent DIR and G inputs per side, enabling flexible direction arbitration in multi-bus systems. It supports true 3-state isolation with power-down protection on all I/Os and guarantees PCI bus levels at 24 mA sink/source.

Bus-hold circuitry maintains valid logic states on floating data inputs without external biasing, and symmetrical tPLH ≅ tPHL ensures balanced rise/fall timing critical for synchronous bus handshaking. All I/Os feature ESD protection exceeding 2 kV HBM and latch-up immunity >500 mA per JESD17.

Key Specifications

Pinout & Package

TSSOP-48 package with 0.5 mm pitch, 12.6 mm × 8.1 mm body, 1.2 mm max height, and exposed thermal pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit bidirectional bus transceiver applications.

Compared with 74ALVCH16245QTR and SN74LVC16245ADGGR, the 74LCXH16245TTR uniquely combines 5 V I/O tolerance, integrated bus-hold, and symmetrical ±24 mA drive - making it optimal for legacy interface consolidation where reliability, component count reduction, and mixed-voltage interoperability are mandatory.

Availability

74LCXH16245TTR is available at Aetrix Electronics and suitable for PCI add-in card design, 3.3 V/5 V mixed-voltage backplanes, and low-power industrial controller expansion requiring stable component supply across extended temperature ranges (–55 °C to +125 °C).

Supply support for 74LCXH16245TTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The 74LCXH series targets low-voltage, high-speed logic interfacing in mixed-supply systems, emphasizing 5 V tolerance, bus-hold integration, and AC/ACT-equivalent performance at 3.3 V operation.

FAQ

Can 74LCXH16245TTR be used with a 2.5 V supply?

Yes - the device is specified for VCC = 2.0 V to 3.6 V, and all DC/AC parameters including tPD (max 5.3 ns), IOL/IOH (±12 mA at VCC = 2.7 V), and VIH/VIL thresholds remain guaranteed across this range. At 2.5 V, output swing is 0–2.5 V with 5 V-tolerant inputs still functional.

Does the bus-hold feature work when VCC = 0 V?

No - bus-hold requires VCC ≥ 1.5 V to retain data; below that threshold, inputs enter high-impedance mode and are unprotected. However, power-down protection prevents reverse current flow, allowing safe hot-insertion into live 5 V backplanes even with VCC unpowered.

What is the maximum clock frequency supported for burst-mode data transfer?

The device itself has no internal clock; its usable data rate depends on system-level timing margins. With tPD = 4.5 ns and tPZH/tPLZ ≤ 7.2 ns, reliable 100 MHz burst transfers are achievable on well-terminated 50 Ω buses, assuming setup/hold times of ≥2 ns are met by the controlling logic.

Are the DIR and G inputs 5 V tolerant?

Yes - all inputs including DIR and G are rated for VI = –0.5 V to +7.0 V, and function correctly with 0–5.5 V logic swings regardless of VCC. This allows direct connection to 5 V control signals without external resistive dividers or translators.