Texas Instruments CY74FCT273ATSOC

Overview

CY74FCT273ATSOC from Texas Instruments is an 8-bit edge-triggered D-type flip-flop register with common buffered clock (CP) and master-reset (MR) inputs, 7.2 ns maximum propagation delay (tPLH/tPHL), 64 mA output sink current, 32 mA output source current, and SOIC-20 package. It operates across –40°C to +85°C and supports partial-power-down via Ioff.

For engineers reviewing the CY74FCT273ATSOC datasheet, CY74FCT273ATSOC pinout, CY74FCT273ATSOC application, or CY74FCT273ATSOC equivalent, key selection criteria include TTL-compatible input/output levels, matched rise/fall times for noise immunity, edge-rate control circuitry, Ioff-enabled power-down protection, and precise setup/hold timing (tsu = 2 ns, th = 1.5 ns).

Technical Context

This device implements eight synchronous D-type latches triggered on the low-to-high transition of CP, with all Q outputs simultaneously loaded from corresponding D inputs one setup time before the clock edge. MR forces all outputs low asynchronously, independent of CP.

It features FCT-family logic compatibility - fully interoperable with TTL voltage thresholds (VIH = 2 V, VIL = 0.8 V), while delivering reduced VOH (typ. 3.3 V) and enhanced noise immunity via edge-rate control and matched switching characteristics. Ioff circuitry disables outputs when VCC = 0 V, preventing backflow during partial power-down.

Key Specifications

Pinout & Package

Package: SOIC-20 (DW), 7.5 mm × 12.8 mm body, 1.27 mm pitch, RoHS-compliant NIPDAU lead finish, MSL Level-1 (unlimited reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit register applications.

Compared with CY74FCT273ATSOC, CY74FCT273ATSOCT offers identical functionality in tape-and-reel format for SMT efficiency, while CY74FCT273CTSOC trades drive strength and speed for lower power consumption - enabling optimization for either performance headroom or energy-constrained operation.

Availability

CY74FCT273ATSOC is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and legacy bus interface buffering requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for CY74FCT273ATSOC 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 CY74FCT273ATSOC belongs to TI's FCT logic family, engineered for high-noise-immunity 5-V TTL-compatible digital interfacing in mission-critical industrial and automotive control systems.

FAQ

What is the maximum clock frequency supported by CY74FCT273ATSOC?

CY74FCT273ATSOC does not specify a maximum clock frequency in its datasheet; instead, it defines minimum pulse widths (t_w = 6 ns for CP and MR) and timing margins (t_su = 2 ns, t_h = 1.5 ns). Based on these, reliable operation is guaranteed up to approximately 83 MHz (1 / (2 × 6 ns)) in ideal conditions, though system-level timing analysis including board trace delays and load capacitance must be performed for actual design validation. CY74FCT273ATSOC remains functional well beyond this theoretical limit when timing margins are preserved.

Does CY74FCT273ATSOC support 3.3-V operation?

No, CY74FCT273ATSOC is specified only for 4.75 V to 5.25 V supply operation per its recommended operating conditions. Its input thresholds (VIH = 2 V, VIL = 0.8 V) and output drive characteristics are optimized for 5-V TTL compatibility. Applying 3.3 V to VCC violates the minimum supply requirement and will result in undefined logic behavior, insufficient noise margin, and potential failure to meet timing specifications. For 3.3-V systems, consider TI's LVC or AUC logic families instead of CY74FCT273ATSOC.

How does the Ioff feature function in CY74FCT273ATSOC during partial power-down?

In CY74FCT273ATSOC, the Ioff circuitry activates automatically when VCC = 0 V, disabling all outputs and limiting leakage current to ±1 µA per pin even if input or output voltages reach up to 4.5 V. This prevents reverse current flow from powered sections of the system into the unpowered CY74FCT273ATSOC, protecting both the device and upstream drivers. The feature requires no external control signal and operates independently of MR or CP states - a critical safeguard in hot-swap and modular power architectures using CY74FCT273ATSOC.

Can CY74FCT273ATSOC be used as a replacement for standard 74LS273?

Yes, CY74FCT273ATSOC is pin-compatible and functionally equivalent to 74LS273 but with significant enhancements: higher output drive (64 mA sink vs. ~8 mA), faster propagation (7.2 ns vs. ~17 ns), lower power consumption, and added Ioff and edge-rate control. It accepts identical TTL input levels and delivers TTL-compatible outputs, making it a direct drop-in upgrade. However, verify that the improved speed does not introduce timing violations in legacy designs originally tuned for LS-family delays - CY74FCT273ATSOC may require minor layout or timing constraint adjustments in such cases.

What is the thermal resistance (θJA) of CY74FCT273ATSOC in its SOIC-20 package?

The junction-to-ambient thermal resistance (θJA) of CY74FCT273ATSOC in the SOIC-20 (DW) package is 58°C/W, as specified in the absolute maximum ratings table. This value assumes standard JEDEC test board conditions (2S2P, 1-inch² copper pad). Actual thermal performance in end equipment depends on PCB layout - adding thermal vias under the exposed pad (if present) and increasing copper area can reduce effective θJA. For continuous operation at full output drive, ensure ambient temperature stays within the –40°C to +85°C range and power dissipation remains below the derated limit implied by θJA and maximum junction temperature (125°C).