STMicroelectronics 74LCX16245TTR

Overview

74LCX16245TTR from STMicroelectronics is a low-voltage CMOS 16-bit bus transceiver (3-state) with 5V-tolerant inputs/outputs, 4.5 ns max propagation delay at 3V, ±24 mA output drive, and 2.0–3.6 V operating range. It enables bidirectional asynchronous data transfer between 3.3V buses interfaced to 5V logic, used in PCI-compliant backplane interfaces and memory expansion subsystems.

For engineers reviewing the 74LCX16245TTR datasheet, 74LCX16245TTR pinout, 74LCX16245TTR application, or 74LCX16245TTR equivalent, key selection criteria include 5V tolerance on all I/Os, symmetrical 24 mA drive capability, TSSOP-48 package compatibility, and DIR/G-controlled bidirectional flow with high-impedance isolation.

Technical Context

This transceiver implements dual 8-bit bidirectional data paths controlled by independent DIR and G inputs per side, supporting simultaneous A→B and B→A transfers only when enabled and directionally aligned. Its C2MOS process ensures latch-up immunity >500 mA and ESD robustness (HBM >2 kV), critical for hot-swap-capable backplanes.

Propagation delays are balanced (tPLH ≅ tPHL), skew is limited to 1.0 ns across outputs, and power-down protection maintains input/output integrity during VCC = 0 V. All I/Os tolerate 0–5.5 V regardless of VCC, enabling mixed-voltage system interconnect without level shifters.

Key Specifications

Pinout & Package

TSSOP-48 package: 12.6 mm × 8.1 mm body, 0.5 mm pitch, 48 leads, exposed pad not present, RoHS-compliant matte tin finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74ALVC16245PW and SN74LVC16245ADGGR, the 74LCX16245TTR delivers superior latch-up immunity (500 mA vs. unspecified), guaranteed data retention down to 1.5 V, and lower quiescent current-making it optimal for industrial hot-swap and ultra-low-power standby modes.

Availability

74LCX16245TTR is available at Aetrix Electronics and suitable for PCI bus interfaces, memory expansion modules, hot-swappable backplanes, and low-power FPGA I/O bridging requiring stable component supply across extended temperature ranges.

Supply support for 74LCX16245TTR 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 industrial, automotive, and consumer markets.

The 74LCX logic family targets high-speed, low-voltage 3.3 V systems requiring 5 V signal interoperability, emphasizing robustness, timing precision, and power efficiency in space-constrained applications.

FAQ

Can 74LCX16245TTR operate with VCC = 2.5 V while driving 5 V signals?

Yes. The device operates within 2.0–3.6 V VCC range and tolerates 0–5.5 V on all I/O pins regardless of supply voltage. At VCC = 2.5 V, output high voltage (VOH) is guaranteed ≥2.0 V at ±12 mA, sufficient to meet 5 V TTL input thresholds (≥2.0 V for VIH).

What is the maximum bus capacitance supported at 25 MHz operation?

With CL = 50 pF and RL = 500 Ω, propagation delay remains ≤4.5 ns up to 25 MHz. Total bus capacitance must stay ≤50 pF (including trace, connector, and load contributions) to maintain timing margins; exceeding this increases tPD and risks setup/hold violations.

How does the power-down protection function when VCC = 0 V?

When VCC = 0 V, all inputs and outputs enter a high-impedance, non-destructive state with Ioff leakage ≤10 µA at 5.5 V applied. This prevents current injection into the unpowered die and avoids bus contention, enabling true hot-plug capability without auxiliary circuitry.

Are the DIR and G inputs 5 V tolerant?

Yes. DIR (pins 1, 24) and G (pins 25, 48) are fully 5 V tolerant - they accept 0–5.5 V logic levels independent of VCC. This allows direct control from 5 V microcontrollers or CPLDs without pull-up resistors or voltage dividers.