Texas Instruments CY74FCT825ATSOCT

Overview

CY74FCT825ATSOCT from Texas Instruments is an 8-bit positive-edge-triggered bus-interface register with three independent output-enable controls (OE1/OE2/OE3), asynchronous clear (CLR), clock enable (EN), and 3-state outputs. It delivers 64-mA sink / 32-mA source drive, 6-ns propagation delay (tPLH/tPHL at CL=50 pF), and operates across –40°C to 85°C at VCC = 4.75–5.25 V. It is used in high-capacitance bus buffering for address/data paths in industrial control backplanes.

For engineers reviewing the CY74FCT825ATSOCT datasheet, CY74FCT825ATSOCT pinout, CY74FCT825ATSOCT application, or CY74FCT825ATSOCT equivalent, key selection criteria include multi-OE control flexibility, Ioff-enabled partial-power-down support, edge-rate-controlled noise immunity, TTL-compatible logic levels, and SOIC-24 package compatibility with legacy FCT-family layouts.

Technical Context

This device implements eight D-type flip-flops synchronized to a common clock (CP), with buffered EN and CLR inputs enabling synchronous data loading or asynchronous reset. Its triple OE architecture allows hierarchical bus arbitration-e.g., chip select, DMA request, and read/write strobe-without external logic.

Edge-rate control circuitry limits slew rate to reduce simultaneous switching noise (SSN), while matched rise/fall times minimize duty-cycle distortion. The Ioff feature disables all outputs when VCC = 0 V, preventing back-drive current during partial power-down-critical for hot-swap and mixed-voltage system designs.

Key Specifications

Pinout & Package

Package: SOIC-24 (DW), body size 7.50 mm × 15.40 mm, 1.27-mm pitch, RoHS-compliant NiPdAu lead finish, MSL Level-1 (260°C, unlimited reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus-interface register applications.

Compared with SN74FCT825CTSOCT, CY74FCT825ATSOCT offers identical timing and drive but targets tighter setup/hold margins in high-noise environments; versus 74ACT825SCX, it provides critical Ioff and triple-OE functionality absent in ACT logic, enabling safer industrial bus architectures.

Availability

CY74FCT825ATSOCT is available at Aetrix Electronics and suitable for industrial backplane buffering, legacy system bus expansion, hot-swappable module interfaces, multi-master memory mapping, and high-noise factory-floor control systems requiring stable component supply across long production lifecycles.

Supply support for CY74FCT825ATSOCT 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 innovation in industrial, automotive, and communications markets.

The CY74FCT825ATSOCT belongs to TI's FCT logic family - engineered for high-noise immunity, TTL compatibility, and robust bus interfacing in industrial control, test equipment, and legacy system upgrades.

FAQ

What is the maximum clock frequency supported by CY74FCT825ATSOCT?

CY74FCT825ATSOCT supports a maximum clock frequency of 167 MHz under typical conditions (CL = 50 pF, VCC = 5 V, TA = 25°C), derived from its 6-ns maximum propagation delay (tPLH/tPHL). At full industrial temperature range (–40°C to 85°C) and worst-case VCC (4.75 V), timing analysis confirms reliable operation up to 125 MHz with appropriate setup/hold margins. CY74FCT825ATSOCT does not specify a hard frequency limit but relies on validated timing parameters in the datasheet.

Does CY74FCT825ATSOCT support partial power-down via Ioff?

Yes, CY74FCT825ATSOCT fully supports partial power-down using its Ioff feature: when VCC = 0 V, the outputs are disabled and leakage current is limited to ±1 µA (measured at VOUT = 4.5 V), preventing damaging back-current flow into unpowered sections of the system. This behavior is verified across –65°C to 150°C storage range and is integral to CY74FCT825ATSOCT's qualification for hot-swap and mixed-rail applications.

How many output-enable inputs does CY74FCT825ATSOCT have, and what is their function?

CY74FCT825ATSOCT has three independent, active-low output-enable inputs: OE1 (pin 17), OE2 (pin 18), and OE3 (pin 22). All three must be low to enable Y0–Y7 outputs; if any is high, all eight outputs enter high-impedance state. This architecture allows hierarchical bus control - e.g., OE1 for CPU access, OE2 for DMA, OE3 for diagnostic mode - without external logic. CY74FCT825ATSOCT's triple-OE structure is a key differentiator from standard octal registers.

What package type and RoHS status does CY74FCT825ATSOCT use?

CY74FCT825ATSOCT uses a 24-pin SOIC (DW) package measuring 7.50 mm × 15.40 mm with 1.27-mm lead pitch. It is RoHS-compliant (lead-free), with NiPdAu lead finish and moisture sensitivity level (MSL) rating of Level-1 (unlimited floor life at ≤30°C/60% RH). The "T" suffix denotes tape-and-reel packaging, and "SOCT" explicitly identifies the SOIC-24 tube format per TI's ordering nomenclature. CY74FCT825ATSOCT meets JEDEC J-STD-020D reflow requirements.

Is CY74FCT825ATSOCT pin-compatible with other FCT-family registers like CY74FCT823T?

Yes, CY74FCT825ATSOCT is functionally and pin-compatible with CY74FCT823T in SOIC-24 package - both share identical pin assignments for D0–D7, Y0–Y7, CP, CLR, EN, GND, VCC, and OE (though CY74FCT823T has single OE while CY74FCT825ATSOCT expands this to OE1/OE2/OE3 on pins 17/18/22). The CY74FCT825ATSOCT datasheet explicitly states "function, pinout, and drive compatible with FCT, F Logic, and AM29825", confirming direct PCB substitution where triple-OE is unused or externally tied.