STMicroelectronics 74VCXH162245TTR

Overview

74VCXH162245TTR from STMicroelectronics is a low-voltage CMOS 16-bit bus transceiver (3-state) with dual-voltage operation (2.3V–3.6V), 3.6V-tolerant I/O, and asymmetric drive strength: A-side outputs deliver ±12 mA at 3.0V, B-side outputs deliver ±24 mA at 3.0V, and propagation delays are as low as 2.5 ns (B→A, VCC = 3.0–3.6V). It enables bidirectional data flow between mismatched voltage domains in high-speed memory or peripheral interconnects.

For engineers reviewing the 74VCXH162245TTR datasheet, 74VCXH162245TTR pinout, 74VCXH162245TTR application, or 74VCXH162245TTR equivalent, key selection criteria include directional control logic (DIR/G inputs), bus-hold functionality eliminating external biasing, integrated 26Ω series resistors on A-port outputs for EMI suppression, and differential drive capability across two independent 8-bit ports.

Technical Context

This transceiver implements true bidirectional asynchronous communication via two independent direction-control inputs (1DIR, 2DIR) and two output-enable inputs (1G, 2G), allowing per-port isolation and independent data flow control. Each port features bus-hold circuitry on all data terminals (1A1–1A8, 1B1–1B8, 2A1–2A8, 2B1–2B8), maintaining last-valid logic state without external pull resistors.

The device integrates 26Ω series termination on all A-port outputs to damp signal reflections in high-speed PCB traces, while B-port outputs provide higher drive strength for driving heavier loads or longer stubs. Input and output structures support hot-swap compatibility and power-down protection, with I/O tolerance up to 3.6V regardless of VCC (2.3V–3.6V).

Key Specifications

Pinout & Package

TSSOP-48 package (12.6 mm × 8.1 mm, 0.5 mm pitch) with exposed thermal pad; 48-pin thin shrink small-outline package optimized for high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC162245ADGGR and 74ALVC162245PW, the 74VCXH162245TTR uniquely combines asymmetric drive, integrated termination, and bus hold - reducing component count, improving noise margin, and simplifying power sequencing in mixed-voltage industrial and memory interfaces.

Availability

74VCXH162245TTR is available at Aetrix Electronics and suitable for memory subsystem interconnect, peripheral bridge interface, hot-swappable module backplane, and industrial PLC I/O expansion requiring stable component supply across extended temperature ranges (–55°C to +125°C).

Supply support for 74VCXH162245TTR 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, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer applications.

The VCXH logic family targets low-voltage, high-speed bidirectional bus interfacing with enhanced robustness - specifically engineered for mixed-supply systems where noise immunity, voltage tolerance, and layout simplicity are critical.

FAQ

Can 74VCXH162245TTR operate with VCC = 2.5V while interfacing with 3.6V signals?

Yes. The device supports VCC as low as 2.3V and guarantees full 3.6V tolerance on all inputs and outputs per absolute maximum ratings and DC specifications. At VCC = 2.5V, B-side outputs deliver ±18 mA minimum, and propagation delay remains ≤4.3 ns (B→A), enabling reliable operation in mixed-voltage systems without external level shifters.

What is the function of the 26Ω series resistors on the A-port outputs?

The 26Ω resistors are monolithically integrated into each A-port output driver stage to suppress signal reflections and reduce EMI in high-speed PCB traces. They are not present on B-port outputs, enabling higher drive strength where needed. This eliminates the need for discrete series termination resistors and reduces layout complexity and BOM count.

How does bus-hold functionality behave during power-down or VCC = 0V?

Bus-hold remains active as long as VCC ≥ 0.5V and input voltage stays within –0.5V to VCC + 0.5V. When VCC = 0V, bus-hold is disabled, but power-down protection clamps all I/O to safe voltage limits (–0.5V to 3.6V), preventing back-driving or latch-up. No external hold circuitry is required during normal operation or brown-out conditions.

Is 74VCXH162245TTR pin-compatible with standard 74HCT162245 devices?

No. While functionally similar as a 16-bit transceiver, the 74VCXH162245TTR uses a 48-pin TSSOP package with different pin mapping - notably separate DIR and G inputs per port, and interleaved A/B port assignments. It is pin- and function-compatible only with the 74VCXH162245 family (e.g., TTR, T, and R variants), not legacy 74HCT or 74LVCH parts.