Texas Instruments CY74FCT823ATSOCT

Overview

CY74FCT823ATSOCT from Texas Instruments is a 9-bit bus-interface register with 3-state outputs, positive-edge-triggered D-type flip-flops, buffered clock-enable (EN) and asynchronous clear (CLR), and Ioff support for partial-power-down operation. It delivers 64 mA sink / 32 mA source drive, 10 ns propagation delay (tPLH/tPHL at CL = 50 pF), and TTL-compatible input/output logic levels - designed for high-capacitance bus loading in parity and address/data path expansion within microprogrammed systems.

For engineers reviewing the CY74FCT823ATSOCT datasheet, CY74FCT823ATSOCT pinout, CY74FCT823ATSOCT application, or CY74FCT823ATSOCT equivalent, key selection criteria include 9-bit parallel register functionality, 3-state output control timing (tPZL/tPHZ), Ioff-enabled power-down isolation, edge-rate-controlled noise immunity, and SOIC-24 package compatibility with legacy FCT-family layouts.

Technical Context

This device implements nine independent D-type flip-flops synchronized to the rising edge of CP, with shared EN (clock enable) and CLR (asynchronous clear) inputs driving all bits simultaneously. Output enable (OE) controls 3-state Y outputs independently of register state, enabling bus sharing without data corruption.

It features edge-rate control circuitry to reduce simultaneous switching noise, matched rise/fall times for clean signal integrity, and Ioff protection that disables outputs when VCC = 0 V - preventing backflow current during partial power-down. Input thresholds meet TTL specifications (VIH = 2.0 V min, VIL = 0.8 V max), ensuring interoperability with legacy 5-V logic families.

Key Specifications

Pinout & Package

Package: SOIC-24 (DW), 300-mil body width, RoHS-compliant, moisture sensitivity level (MSL) Level-1 (unlimited floor life at <30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 9-bit bus-interface register applications.

Compared with CY74FCT823CTSOCT, CY74FCT823ATSOCT trades 4 ns of speed for improved noise characteristics and relaxed timing constraints; versus SN74FCT823ATSOP, it delivers 21°C/W lower thermal resistance and surface-mount manufacturability without sacrificing logic or drive compatibility.

Availability

CY74FCT823ATSOCT is available at Aetrix Electronics and suitable for parity bus interfacing, microprogrammed control store implementation, and high-capacitance address/data path buffering requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant manufacturing.

Supply support for CY74FCT823ATSOCT 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 decades of expertise in high-reliability 5-V logic families.

CY74FCT823ATSOCT belongs to TI's FCT logic family - engineered for noise-immune, high-drive 5-V bus interfacing in industrial, computing, and communications infrastructure where timing precision and power-down safety are critical.

FAQ

What is the maximum clock frequency supported by CY74FCT823ATSOCT?

CY74FCT823ATSOCT supports reliable operation up to 100 MHz based on its 10 ns maximum propagation delay (tPLH/tPHL) and 4 ns minimum setup time (tsu). At CL = 50 pF and TA = 85°C, timing margins remain sufficient for synchronous systems requiring deterministic register-to-bus transfer without added wait states. The CY74FCT823ATSOCT is not characterized for guaranteed operation beyond this frequency under worst-case conditions.

Does CY74FCT823ATSOCT support partial power-down via Ioff?

Yes, CY74FCT823ATSOCT includes Ioff circuitry that actively disables all outputs when VCC = 0 V, preventing damaging current backflow from live buses into the unpowered device. This feature is fully specified per JESD78 and verified across –40°C to 85°C, making CY74FCT823ATSOCT suitable for hot-swap and modular power architectures where subsystems power up/down independently.

How does CY74FCT823ATSOCT differ from standard FCT-family registers like CY74FCT823CTSOCT?

CY74FCT823ATSOCT is the 10 ns speed grade variant of the FCT823 family, whereas CY74FCT823CTSOCT is the 6 ns grade. Both share identical pinout, Ioff support, 3-state control, and TTL-compatible interfaces. The CY74FCT823ATSOCT uses edge-rate control to improve noise immunity at the expense of raw speed - making it preferable in electrically noisy environments where signal integrity outweighs marginal timing gains.

Can CY74FCT823ATSOCT be used as a direct replacement for AM29823 in existing designs?

Yes, CY74FCT823ATSOCT is functionally, electrically, and pinout-compatible with AM29823, including identical SOIC-24 packaging, 9-bit register architecture, EN/CLR/OE control structure, and 5-V TTL interface levels. No PCB changes are required; however, verify timing margins (CY74FCT823ATSOCT tPLH/tPHL = 10 ns vs. AM29823 = 12 ns) to ensure backward compatibility in timing-critical paths.

What are the thermal characteristics of CY74FCT823ATSOCT in SOIC-24 package?

CY74FCT823ATSOCT in SOIC-24 (DW package) has a junction-to-ambient thermal resistance (θJA) of 46°C/W per JEDEC JESD51-7. At full 64 mA output sink per pin and worst-case ambient temperature (85°C), junction temperature remains within safe operating limits (<125°C) with typical PCB copper area. This θJA value is 21°C/W lower than the DIP-24 variant, confirming SOIC-24's superior thermal performance for sustained high-drive operation.