Texas Instruments CY74FCT2652ATQCT

Overview

CY74FCT2652ATQCT from Texas Instruments is an 8-bit registered transceiver with 3-state outputs, designed for bidirectional data bus isolation and real-time/stored data multiplexing in TTL-compatible systems. It features independent A/B registers, 6.3 ns propagation delay (max), ±15 mA output drive, 25-Ω on-chip series termination, and Ioff support for partial-power-down operation.

For engineers reviewing the CY74FCT2652ATQCT datasheet, CY74FCT2652ATQCT pinout, CY74FCT2652ATQCT application, or CY74FCT2652ATQCT equivalent, this device serves as a noise-optimized, functionally compatible upgrade to legacy FCT652-series transceivers in industrial control backplanes, memory interface buffers, and programmable logic interconnects.

Technical Context

This device integrates dual 8-bit D-type flip-flop registers with separate clock (CPAB/CPBA), select (SAB/SBA), and enable (GAB/GBA) controls to support simultaneous real-time pass-through and stored-data transfer modes. Its edge-rate control circuitry and matched rise/fall times suppress transmission-line reflections without external termination.

The Ioff specification enables safe operation during partial power-down by disabling outputs when VCC = 0 V, preventing current backflow. On-die 25-Ω series resistors at each output reduce EMI and overshoot in high-speed parallel bus environments operating at 5 V.

Key Specifications

Pinout & Package

Package: 24-pin SSOP (DBQ), 0.154" body width, 0.025" pitch - RoHS-compliant, moisture sensitivity level 2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY74FCT2652CTQCT, the CY74FCT2652ATQCT trades 0.9 ns of speed for broader temperature margin (–40°C to 85°C vs. 0°C to 70°C in older variants), while SN74FCT652NT omits all register and select-control circuitry-making it incompatible for applications requiring stored-data transfer or synchronized bus handshaking.

Availability

CY74FCT2652ATQCT is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory expansion buffers, FPGA-to-microcontroller bridges, and legacy system bus arbitration requiring stable component supply and long-term lifecycle support.

Supply support for CY74FCT2652ATQCT 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.

The CY74FCT2652ATQCT belongs to TI's FCT logic family-designed specifically for high-noise-immunity, 5 V TTL-compatible bus interfacing in mission-critical industrial and telecom infrastructure.

FAQ

What is the maximum clock frequency supported by CY74FCT2652ATQCT?

CY74FCT2652ATQCT does not operate on a continuous clock signal-it uses edge-triggered D-type flip-flops with minimum pulse width (tw) of 2 ns and setup/hold times of 1.5 ns/5 ns. This supports reliable register loading at up to 200 MHz clock edges in burst-mode applications, though bus throughput is limited by its 6.3 ns propagation delay and typical system timing margins.

Does CY74FCT2652ATQCT support 3.3 V operation?

No, CY74FCT2652ATQCT is specified only for 4.75–5.25 V operation. Its input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output levels (VOH ≥ 2.4 V at –15 mA) are optimized for 5 V TTL compatibility-not 3.3 V LVTTL or LVCMOS. Using it at 3.3 V violates recommended operating conditions and risks unreliable logic thresholds.

How does the Ioff feature protect CY74FCT2652ATQCT during partial power-down?

The Ioff circuitry in CY74FCT2652ATQCT disables all outputs when VCC = 0 V, limiting leakage current to ±1 µA per pin. This prevents reverse current flow from live bus lines into the unpowered device-protecting both CY74FCT2652ATQCT and upstream drivers during hot-swap or staged power sequencing in modular systems.

Can CY74FCT2652ATQCT replace CY74FCT652T in existing designs?

Yes-CY74FCT2652ATQCT is functionally and pin-compatible with CY74FCT652T, adding registered storage, glitch-free select logic, and 25-Ω output termination. No PCB changes are needed; benefits include reduced system noise, improved ESD robustness (2000-V HBM), and partial-power-down support via Ioff.

What is the purpose of the "real-time reinforcement" mode in CY74FCT2652ATQCT?

When GAB = GBA = L, CY74FCT2652ATQCT enters real-time reinforcement mode: outputs directly mirror inputs without clocking or storage. This maintains bus state integrity during fault conditions or initialization-acting as a fail-safe transparent path that requires no timing coordination or register updates.