Texas Instruments CY74FCT245CTSOC

Overview

CY74FCT245CTSOC from Texas Instruments is an 8-bit noninverting bidirectional transceiver with 3-state outputs, designed for bus-oriented data transfer between TTL-compatible systems. It features 64-mA sink / 32-mA source drive strength, 4.1-ns max propagation delay (tPLH/tPHL), and operates at 4.75–5.25 V over –40°C to 85°C. Used in industrial control backplanes and legacy microprocessor data buses.

For engineers reviewing the CY74FCT245CTSOC datasheet, CY74FCT245CTSOC pinout, CY74FCT245CTSOC application, or CY74FCT245CTSOC equivalent, key selection criteria include 3-state bus isolation timing, Ioff partial-power-down support, matched rise/fall times, and SOIC-20 package compatibility with legacy PCB layouts.

Technical Context

This device implements dual-directional data flow controlled by a single transmit/receive (T/R) input and independent output enable (OE). Its edge-rate control circuitry reduces switching noise while maintaining full TTL-level compatibility on both inputs and outputs.

The Ioff feature disables outputs when VCC = 0 V, preventing backflow current during partial power-down-critical for hot-swap and mixed-voltage system designs. Matched rise/fall times (typical 3.5 ns) minimize skew across all eight channels under load.

Key Specifications

Pinout & Package

SOIC-20 (DW) package, 7.5 mm × 12.8 mm body, 1.27 mm pitch, 2.65 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1 (unlimited reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY74FCT245ATSOC and SN74FCT245CTSO, the CY74FCT245CTSOC delivers the fastest timing (4.1 ns) in the FCT245C speed grade while retaining full pin, function, and thermal compatibility-making it optimal for timing-critical industrial backplane upgrades.

Availability

CY74FCT245CTSOC is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy microprocessor bus extensions, and automated test fixture designs requiring stable component supply and long-term obsolescence management.

Supply support for CY74FCT245CTSOC 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, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The CY74FCT245 series belongs to TI's Fast CMOS Technology (FCT) logic family, engineered for high-speed, low-noise, TTL-compatible bus interfacing in mission-critical industrial systems.

FAQ

What is the maximum operating frequency supported by the CY74FCT245CTSOC?

The CY74FCT245CTSOC does not specify a maximum clock frequency directly, but its 4.1-ns maximum propagation delay (tPLH/tPHL) supports reliable operation on buses clocked up to approximately 100 MHz with adequate setup/hold margins. Actual usable frequency depends on trace length, load capacitance, and system timing constraints-notably, the device is commonly deployed in 25-MHz industrial backplanes and 20-MHz Z80/8086 extensions where its timing guarantees ensure deterministic behavior. The CY74FCT245CTSOC is rated for continuous operation across its full –40°C to +85°C range.

Does the CY74FCT245CTSOC support partial power-down operation?

Yes, the CY74FCT245CTSOC includes Ioff circuitry that actively disables outputs when VCC = 0 V, limiting off-state current to ±1 µA even with input/output voltages up to 4.5 V. This feature enables safe partial-power-down operation-critical for hot-swap backplanes and mixed-voltage systems. During Ioff mode, the CY74FCT245CTSOC prevents damaging current backflow into unpowered sections of the board, satisfying industrial safety requirements without external isolation components.

What is the pinout compatibility status of CY74FCT245CTSOC with other FCT245 variants?

The CY74FCT245CTSOC uses the standard SOIC-20 (DW) package with identical pinout to CY74FCT245ATSOC, CY74FCT245TSOC, and SN74FCT245CTSO. All share the same A0–A7 (pins 1–8), B0–B7 (pins 11,13–19), T/R (pin 12), OE (pin 20), VCC (pin 10), and GND (pin 9) assignment. This pin-for-pin compatibility allows direct substitution in existing layouts-no PCB changes required-provided timing and drive requirements are verified against the specific variant's datasheet parameters.

How does the edge-rate control in CY74FCT245CTSOC improve system noise performance?

The CY74FCT245CTSOC integrates internal edge-rate control circuitry that limits the slew rate of output transitions, reducing di/dt-induced ground bounce and crosstalk. This results in significantly improved noise characteristics compared to standard FCT devices-verified by lower simultaneous switching noise (SSN) in multi-bit bus applications. In practice, this allows denser PCB layouts and longer trace runs without violating signal integrity budgets, especially critical in industrial control cabinets where multiple CY74FCT245CTSOC devices may share common power/ground planes.

Is the CY74FCT245CTSOC RoHS compliant and what is its moisture sensitivity level?

Yes, the CY74FCT245CTSOC is RoHS compliant (lead-free NiPdAu finish) and rated MSL Level-1 (unlimited floor life) per JEDEC J-STD-020, meaning it can be stored indefinitely at ≤30°C/60% RH without baking prior to reflow. Its SOIC-20 (DW) package has been qualified for standard Pb-free reflow profiles up to 260°C peak temperature, supporting modern manufacturing requirements while maintaining full backward compatibility with legacy 5-V systems.