Texas Instruments CY74FCT245TSOCT

Overview

CY74FCT245TSOCT from Texas Instruments is an 8-bit noninverting bidirectional transceiver with 3-state outputs, designed for bus-oriented data transfer between two 8-bit buses. It features 64-mA sink / 32-mA source drive strength, 4.1 ns max propagation delay (tPLH/tPHL), and operates over –40°C to 85°C with 4.75–5.25 V supply. It enables direction-controlled data flow in industrial control backplanes and legacy TTL-compatible system interconnects.

For engineers reviewing the CY74FCT245TSOCT datasheet, CY74FCT245TSOCT pinout, CY74FCT245TSOCT application, or CY74FCT245TSOCT equivalent, key selection criteria include its 3-state bus isolation capability, Ioff partial-power-down support, matched rise/fall times, edge-rate control for noise reduction, and SOIC-20 package compatibility with legacy 5-V TTL logic levels.

Technical Context

The CY74FCT245TSOCT implements dual 8-bit bidirectional channels controlled by independent T/R (transmit/receive) and OE (output enable) inputs. Its logic diagram confirms noninverting signal path per channel, with high-impedance output state asserted when OE = high regardless of T/R state.

It integrates edge-rate control circuitry to limit slew rate and reduce simultaneous switching noise, and includes Ioff protection that disables outputs and blocks current backflow when VCC = 0 V - enabling safe operation in partial-power-down systems where other rails remain active.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, 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 SN74FCT245SOIC, CY74FCT245TSOCT offers identical performance and drop-in compatibility; versus 74ACT245SCX, it delivers superior drive strength, Ioff protection, and noise control - making it preferred for industrial backplanes and mixed-rail systems.

Availability

CY74FCT245TSOCT is available at Aetrix Electronics and suitable for industrial backplane interconnect, legacy system bus extension, and automated test equipment fixture design requiring stable component supply and long-term lifecycle assurance.

Supply support for CY74FCT245TSOCT 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 specializing in analog, embedded processing, and logic solutions with over 50 years of industrial-grade product development.

The CY74FCT245TSOCT belongs to TI's FCT logic family, engineered specifically for robust 5-V bus interfacing in noise-sensitive, mixed-technology systems requiring TTL compatibility, high drive, and power-aware operation.

FAQ

What is the maximum operating frequency supported by the CY74FCT245TSOCT?

The CY74FCT245TSOCT does not specify a maximum clock frequency but provides propagation delay (tPLH/tPHL) of ≤4.1 ns. This supports reliable data transfer in systems with setup/hold timing budgets allowing ≥240 MHz equivalent toggle rates. Actual usable frequency depends on bus capacitance, termination, and controller timing margins - verified via worst-case timing analysis using tPLH, tPHL, and tPZL values from the datasheet.

Does the CY74FCT245TSOCT support hot-swap or partial-power-down operation?

Yes, the CY74FCT245TSOCT supports partial-power-down via its Ioff circuitry. When VCC = 0 V, Ioff limits output leakage to ±1 µA even with up to 4.5 V applied at I/O pins, preventing damaging current backflow. This enables safe insertion into live backplanes and mixed-rail systems - a key differentiator from standard TTL or ACT logic transceivers.

How does the edge-rate control feature improve system noise performance in the CY74FCT245TSOCT?

The CY74FCT245TSOCT integrates on-die edge-rate control to limit output slew rate, reducing di/dt-induced crosstalk and ground bounce in high-pin-count parallel buses. This results in significantly cleaner signal integrity on shared PCB traces and lower EMI emissions - especially critical in dense industrial control boards where multiple CY74FCT245TSOCT devices drive common backplane segments simultaneously.

Can the CY74FCT245TSOCT interface directly with 3.3-V logic devices?

The CY74FCT245TSOCT has TTL-compatible inputs (VIH = 2.0 V min) and outputs VOH ≈ 3.3 V (typical at VCC = 5 V, IOH = –32 mA), making it suitable for driving 3.3-V CMOS inputs. However, its 5-V supply means outputs swing to 5 V when loaded lightly - use series resistors or verify receiver VIH(max) tolerance. For guaranteed 3.3-V–compatible operation, pair with a dedicated level shifter or select a dual-supply transceiver.

What is the thermal resistance (θJA) of the CY74FCT245TSOCT in its SOIC-20 package?

The CY74FCT245TSOCT in SOIC-20 (DW) package has a specified junction-to-ambient thermal resistance (θJA) of 58°C/W under JEDEC-standard PCB mounting conditions (2-layer board, 1 in² copper). This value assumes proper thermal vias and copper pour - actual θJA may vary with PCB layout, airflow, and adjacent heat sources. Derate power dissipation accordingly for operation above 25°C ambient.