STMicroelectronics 74LVX245TTR

Overview

74LVX245TTR from STMicroelectronics is a low-voltage CMOS octal bus transceiver (3-state) with 5V-tolerant inputs, designed for bidirectional asynchronous data bus interfacing between 3.3V and 5V systems. It features symmetrical output drive (±4 mA), propagation delay of 4.7 ns (typ. at VCC = 3.3V), and operates across 2V–3.6V supply range - ideal for battery-powered, low-noise embedded communication interfaces.

For engineers reviewing the 74LVX245TTR datasheet, 74LVX245TTR pinout, 74LVX245TTR application, or 74LVX245TTR equivalent, key selection criteria include 5V input tolerance, directional control (DIR) and output enable (G) logic behavior, high-impedance isolation timing (tPZL/tPLZ), and ESD immunity (2 kV HBM).

Technical Context

This device implements dual-bus bidirectional data flow controlled by DIR and G inputs: when G = L, data flows A→B if DIR = L or B→A if DIR = H; when G = H, all outputs enter high-impedance state. Power-down protection allows 0–7V input voltage regardless of VCC, enabling safe hot-plug and mixed-voltage interface operation.

It uses sub-micron C2MOS technology to achieve true CMOS low quiescent current (ICC ≤ 4 µA) while maintaining high-speed performance. Input thresholds are fixed (VIL = 0.8V, VIH = 2.0V at VCC = 3V), independent of supply, and output impedance is balanced (|IOH| = IOL ≥ 4 mA), minimizing signal skew and ground bounce in multi-bit buses.

Key Specifications

Pinout & Package

TSSOP-20 package (6.5 mm × 4.4 mm, 0.65 mm pitch), thin shrink small outline with exposed pad not present; RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245APWR and 74ALVC245MTCX, the 74LVX245TTR uniquely combines 7 V input survivability, true 5V tolerance during operation, and sub-5 ns propagation delay - making it the only choice for robust 3.3V/5V bridging in industrial and automotive environments where supply sequencing is uncontrolled.

Availability

74LVX245TTR is available at Aetrix Electronics and suitable for industrial PLC backplanes, portable medical sensor hubs, and automotive body control modules requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for 74LVX245TTR 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, specializing in automotive, industrial, and power management ICs with strong analog and mixed-signal design heritage.

The LVX logic family targets low-voltage, low-power, and mixed-signal interface applications - specifically engineered for seamless voltage translation and noise-resilient operation in battery-constrained and electrically harsh environments.

FAQ

Can the 74LVX245TTR operate with VCC = 2.5V while interfacing to 5V inputs?

Yes. The device guarantees 5V-tolerant inputs across its full operating VCC range (2.0–3.6 V). At VCC = 2.5V, VIH remains 2.0V and VIL stays at 0.8V per datasheet Table 6, and absolute maximum VIN is 7V - allowing safe, functional interfacing to 5V logic without external components.

What happens to outputs when VCC = 0V but 5V is applied to inputs?

All inputs are protected by internal circuitry that blocks current flow when VCC = 0V, permitting up to 7V on any input pin without damage or back-powering. Outputs remain in high-impedance state, and no DC path exists from input to output - satisfying hot-swap and partial-power-down requirements.

Is the 74LVX245TTR pin-compatible with standard 74-series 245 devices?

Yes - it is functionally and physically pin-compatible with 74LS245, 74HC245, and 74HCT245 in TSSOP-20 and SO-20 packages. Signal pin order (A/B ports, DIR, G, GND, VCC) matches industry-standard 245 layout, enabling drop-in replacement in existing PCBs with no layout changes.

How does the 74LVX245TTR handle simultaneous switching noise (SSN)?

It minimizes SSN via low VOLP (0.5 V typ. at VCC = 3.3V) and symmetrical output drive (|IOH| = IOL ≥ 4 mA), which equalizes rise/fall times and reduces ground bounce. The C2MOS process and optimized output stage suppress transient current spikes, verified by measured quiet-output voltage under 50 pF load conditions.