Texas Instruments CY74FCT652CTSOC

Overview

CY74FCT652CTSOC from Texas Instruments is an 8-bit registered transceiver with 3-state outputs, designed for bidirectional data bus isolation and multiplexed real-time/stored-data transfer between A and B buses in TTL/CMOS mixed-signal systems. It features independent D-type flip-flop registers per bus, 5.4 ns propagation delay (max), ±32 mA output source/sink capability, and Ioff support for partial-power-down operation.

For engineers reviewing the CY74FCT652CTSOC datasheet, CY74FCT652CTSOC pinout, CY74FCT652CTSOC application, or CY74FCT652CTSOC equivalent, key selection criteria include registered bus arbitration timing, simultaneous real-time + stored-data routing, 5 V TTL-compatible logic levels, and SOIC-24 package compatibility with legacy FCT-family layouts.

Technical Context

This device implements dual 8-bit bidirectional transceivers with edge-triggered D-flip-flops on both A and B buses, enabling synchronized storage of data independent of enable states. Control logic eliminates decoding glitches during transitions between real-time and stored-data modes using dedicated SAB/SBA select inputs.

Each channel supports true 3-state output control via GAB/GBA enables, with matched rise/fall times and edge-rate control circuitry to reduce switching noise. The Ioff feature disables outputs when VCC = 0 V, preventing backflow current during partial power-down sequences in multi-rail systems.

Key Specifications

Pinout & Package

Package: SOIC-24 (DW), 7.5 mm × 15.4 mm body, 1.27 mm pitch, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY74FCT652CTSOC, the ATSOC variant trades 0.9 ns speed for broader timing margin and lower cost, while the TQCT offers identical speed in a compact SSOP package-neither is pin-compatible with SOIC-24 without PCB redesign.

Availability

CY74FCT652CTSOC is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy bus extension systems, and TTL/CMOS bridging applications requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for CY74FCT652CTSOC 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 for industrial, automotive, and communications markets.

CY74FCT652CTSOC belongs to the 74FCT logic family, engineered for high-speed, low-noise 5 V bus interfacing in mission-critical industrial control and data acquisition systems.

FAQ

What is the maximum clock frequency supported by CY74FCT652CTSOC for reliable register operation?

CY74FCT652CTSOC does not specify a maximum clock frequency in its datasheet; instead, it defines minimum pulse width (6 ns) and setup/hold times (4 ns/2 ns). For stable operation, the maximum practical clock rate is ~83 MHz (12 ns period), assuming worst-case timing margins and typical PCB trace loading. This limit derives directly from t_w = 6 ns and t_su + t_th = 6 ns, ensuring reliable edge-triggered register capture in CY74FCT652CTSOC.

Does CY74FCT652CTSOC support hot-swap or live-insertion in powered systems?

Yes, CY74FCT652CTSOC supports partial-power-down via its Ioff circuitry, which disables outputs and limits reverse current to ±1 µA when VCC = 0 V. This allows safe insertion into live backplanes or hot-swappable modules, provided all other signals remain within –0.5 V to 7 V absolute ratings. The feature is explicitly validated in the datasheet's "Ioff" parameter table for CY74FCT652CTSOC.

Can CY74FCT652CTSOC operate with 3.3 V logic inputs while powered at 5 V?

No - CY74FCT652CTSOC requires VCC = 4.75–5.25 V and is specified only for TTL/5 V CMOS input levels (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V). While 3.3 V logic outputs may meet V_IH, they risk violating V_IL margins under noise or temperature variation. TI does not characterize or guarantee 3.3 V input compatibility for CY74FCT652CTSOC.

How does the real-time hold mode work in CY74FCT652CTSOC when GAB and GBA are both low?

When GAB = GBA = L, CY74FCT652CTSOC enters isolation mode: all outputs go high-impedance, and bus lines retain their last driven state only if no other drivers are active. This is not active latching - it relies on bus capacitance and external pull-ups/downs. The datasheet confirms this behavior in the Function Table row "Isolation" for CY74FCT652CTSOC.

What is the thermal resistance (θ_JA) of CY74FCT652CTSOC in its SOIC-24 package?

The SOIC-24 (DW) package for CY74FCT652CTSOC has a specified junction-to-ambient thermal resistance (θ_JA) of 46°C/W under JEDEC-standard conditions. This value assumes a two-layer PCB with minimal copper pour; actual thermal performance depends on board layout, airflow, and adjacent heat sources - all documented in TI's package addendum for CY74FCT652CTSOC.