Texas Instruments CY74FCT273CTQCT

Overview

CY74FCT273CTQCT from Texas Instruments is an 8-bit edge-triggered D-type flip-flop register with common clock (CP) and master-reset (MR) inputs, 5.8 ns maximum propagation delay, 64 mA sink / 32 mA source output drive, and Ioff partial-power-down support. It operates across –40°C to 85°C and is used in synchronous data latching for industrial control bus interfaces.

For engineers reviewing the CY74FCT273CTQCT datasheet, CY74FCT273CTQCT pinout, CY74FCT273CTQCT application, or CY74FCT273CTQCT equivalent, key selection criteria include TTL-compatible input thresholds, matched rise/fall times for EMI reduction, QSOP-20 package footprint, and compatibility with FCT logic families in high-noise digital systems.

Technical Context

This device implements eight independent D-type flip-flops sharing a single positive-edge-triggered clock and asynchronous active-low master reset. All outputs update synchronously on the low-to-high CP transition, with data sampled one setup time before the edge.

It features edge-rate control circuitry to limit slew rate and reduce switching noise, Ioff protection enabling safe operation during partial power-down, and full TTL-level compatibility-both input thresholds (VIH = 2 V min, VIL = 0.8 V max) and output voltage levels (VOH ≥ 2.4 V at –32 mA, VOL ≤ 0.55 V at 64 mA).

Key Specifications

Pinout & Package

Package: QSOP-20 (DBQ), 0.154" body width, 0.65 mm pitch, RoHS-compliant NiPdAu lead finish, MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74FCT273QDR, CY74FCT273CTQCT offers identical logic behavior in a smaller QSOP footprint ideal for space-constrained industrial modules; compared with 74AC273MTCX, it provides superior noise immunity and power-down safety at the cost of slightly lower max frequency headroom.

Availability

CY74FCT273CTQCT is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, and network switch control plane interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY74FCT273CTQCT 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 experience in high-reliability industrial and automotive components.

CY74FCT273CTQCT belongs to TI's FCT logic family, engineered for noise-resilient, TTL-compatible digital interfacing in harsh electromagnetic environments such as factory automation and vehicle electronics.

FAQ

What is the maximum clock frequency supported by CY74FCT273CTQCT?

CY74FCT273CTQCT has a maximum propagation delay of 5.8 ns and minimum pulse width of 6 ns for both CP and MR inputs. Based on these timing parameters, it supports reliable operation up to approximately 85 MHz in well-terminated, low-skew layouts. The device does not specify a hard maximum frequency, but system-level timing margins must account for setup (2 ns) and hold (1.5 ns) requirements relative to the clock edge.

Does CY74FCT273CTQCT support 3.3 V operation?

No, CY74FCT273CTQCT is specified only for 4.75 V to 5.25 V supply operation per its recommended operating conditions. Its TTL-compatible input thresholds and output drive characteristics are optimized for 5 V systems. Using 3.3 V violates the minimum VCC specification and will result in undefined logic levels, reduced noise margin, and potential functional failure.

How does the Ioff feature function in CY74FCT273CTQCT?

In CY74FCT273CTQCT, the Ioff circuitry disables all outputs when VCC = 0 V, limiting leakage current to ±1 µA per terminal. This prevents damaging back-current flow from live buses into a powered-down section of the system - a critical capability for modular systems with hot-swap capability or partial power gating. Ioff is automatic and requires no external control signal.

Can CY74FCT273CTQCT be used as a direct replacement for 74LS273?

Yes, CY74FCT273CTQCT is functionally and pin-compatible with 74LS273, offering identical 8-bit D-register functionality, same pinout (QSOP-20 matches SOIC-20 pin numbering), and TTL-compatible voltage levels. It improves upon LS logic with faster speed (5.8 ns vs. ~15 ns), higher drive strength (64 mA vs. 8 mA sink), and added features like Ioff and edge-rate control - making it a drop-in upgrade for legacy 74LS273 designs.

What is the thermal performance of CY74FCT273CTQCT in its QSOP-20 package?

CY74FCT273CTQCT in the QSOP-20 (DBQ) package has a junction-to-ambient thermal resistance (θJA) of 68°C/W under standard JEDEC test conditions. At maximum rated output current (64 mA sink per pin, worst-case static load), power dissipation remains below 150 mW, resulting in a junction temperature rise of <11°C above ambient - well within safe operating limits for industrial applications up to +85°C ambient.