Texas Instruments CY74FCT2652CTQCTG4

Overview

CY74FCT2652CTQCTG4 from Texas Instruments is an 8-bit registered transceiver with 3-state outputs, dual independent D-type registers (A and B buses), edge-rate control circuitry, and 25-Ω on-chip series output termination. It operates at 5 V, supports real-time or stored data transfer via select-control inputs (SAB/SBA), and enables partial-power-down mode via I_off. Used in high-noise industrial bus interface applications requiring glitch-free multiplexed data routing.

For engineers reviewing the CY74FCT2652CTQCTG4 datasheet, CY74FCT2652CTQCTG4 pinout, CY74FCT2652CTQCTG4 application, or CY74FCT2652CTQCTG4 equivalent, key selection criteria include its 5.4 ns propagation delay (t_PLH/t_PHL), 12 mA sink / 15 mA source drive strength, matched rise/fall times, TTL-compatible logic levels, and QSOP-24 package with I_off support for hot-swap systems.

Technical Context

This device integrates two independent 8-bit D-type flip-flop registers with bidirectional 3-state transceiver logic, enabling simultaneous storage and real-time transfer between A and B buses. Control signals GAB/GBA enable directionality, while SAB/SBA select between live input or registered data without decoding glitches.

Its edge-rate control circuitry and integrated 25-Ω series output resistors suppress transmission-line reflections, reducing system-level noise. The I_off feature disables outputs when V_CC = 0 V, preventing backflow current during partial power-down-critical for mixed-voltage or hot-plug subsystems.

Key Specifications

Pinout & Package

Package: QSOP-24 (SSOP, DBQ), 3.9 mm × 8.7 mm body, 0.635 mm pitch, RoHS-compliant NIPDAU finish, MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY74FCT2652CTQCTG4, the CY74FCT2652ATQCT trades 0.9 ns speed for broader temperature range, while the SN74FCT2652CTSO sacrifices miniaturization and thermal efficiency for assembly flexibility-neither is pin-compatible replacement without layout revision.

Availability

CY74FCT2652CTQCTG4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, automated test equipment controllers, legacy bus extenders, and hot-swappable module interfaces requiring stable component supply across extended product lifecycles.

Supply support for CY74FCT2652CTQCTG4 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 with emphasis on reliability, longevity, and industrial-grade performance.

The CY74FCT family delivers 5-V TTL-compatible logic with enhanced noise immunity and power-down safety-designed specifically for mission-critical industrial, telecom, and instrumentation systems where signal integrity and long-term supply stability are non-negotiable.

FAQ

What is the maximum clock frequency supported by CY74FCT2652CTQCTG4?

CY74FCT2652CTQCTG4 does not specify a maximum clock frequency in its datasheet because it is an edge-triggered register-not a synchronous sequential device with a global clock domain. Its functional limit is determined by setup/hold timing: minimum pulse width (t_w) is 2 ns, and maximum propagation delay is 5.4 ns, supporting reliable operation up to approximately 100 MHz in well-terminated systems with proper PCB layout.

Does CY74FCT2652CTQCTG4 support true bidirectional data flow between A and B buses simultaneously?

No. CY74FCT2652CTQCTG4 supports bidirectional *routing* but not simultaneous A↔B transfer. GAB and GBA are independent enables: when GAB = L and GBA = L, both directions are active-but data flows A→B *or* B→A depending on which select (SAB/SBA) and clock (CPAB/CPBA) controls are asserted. True concurrent bidirectional transfer requires two separate devices or a different architecture.

Can CY74FCT2652CTQCTG4 be used with 3.3-V logic inputs?

Yes-CY74FCT2652CTQCTG4 accepts 3.3-V TTL-compatible inputs directly. Its V_IL (0.8 V max) and V_IH (2.0 V min) thresholds are fully compatible with 3.3-V CMOS logic high/low levels. However, outputs swing to 5-V levels (V_OH ≈ 3.3 V typical), so interfacing to 3.3-V receivers requires level-shifting or verified 5-V-tolerant inputs.

What is the purpose of the 25-Ω output series resistors in CY74FCT2652CTQCTG4?

The 25-Ω on-die series resistors in CY74FCT2652CTQCTG4 dampen signal reflections on PCB traces acting as transmission lines. They match typical FR-4 trace impedance (40–70 Ω) in series with driver output impedance, reducing overshoot/ringing without external components-critical for maintaining signal integrity on >10-cm routes in noisy industrial environments.

How does the I_off feature operate in CY74FCT2652CTQCTG4 during partial power-down?

In CY74FCT2652CTQCTG4, the I_off circuitry activates when V_CC = 0 V, disabling all outputs and presenting high-impedance states regardless of input voltage (up to 4.5 V). This prevents reverse current flow from live buses into the unpowered device-protecting both CY74FCT2652CTQCTG4 and upstream drivers during hot-swap or staged power sequencing.