Texas Instruments CY74FCT2244TQC

Overview

CY74FCT2244TQC from Texas Instruments is an octal noninverting 3-state buffer/line driver with integrated 25-Ω output series resistors, designed for memory address and clock distribution in TTL-compatible systems. It delivers 6.5 ns max propagation delay, ±15 mA output drive, and I_off support for partial-power-down operation across –40°C to 85°C.

For engineers reviewing the CY74FCT2244TQC datasheet, CY74FCT2244TQC pinout, CY74FCT2244TQC application, or CY74FCT2244TQC equivalent, key selection criteria include its QSOP-20 package, 25-Ω on-die termination, TTL-level compatibility, 3-state enable control (OEA/OEB), and I_off-enabled bus isolation during power-down.

Technical Context

This device implements dual independent 4-bit noninverting buffers, each controlled by separate 3-state enable inputs (OEA and OEB). Its edge-rate control circuitry shapes output transitions to suppress transmission-line reflections without external resistors.

The integrated 25-Ω series resistors per output reduce board-level component count and improve signal integrity in high-speed bus applications. I_off functionality ensures outputs remain high-impedance and leakage-limited (<±1 µA) when V_CC = 0 V, enabling safe back-driving in mixed-supply systems.

Key Specifications

Pinout & Package

Package: QSOP-20 (DBQ), 0.154" body width, 0.65 mm pitch, RoHS-compliant green finish, MSL Level-2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer applications.

Compared with SN74F244N and 74ACT244SCX, CY74FCT2244TQC uniquely combines TTL-level compatibility, on-die 25-Ω termination, and I_off protection - making it optimal for noise-sensitive, mixed-power-state industrial bus interfaces where layout space and reliability are critical.

Availability

CY74FCT2244TQC is available at Aetrix Electronics and suitable for memory subsystems, clock distribution networks, industrial backplanes, and legacy TTL upgrades requiring stable component supply and long-term lifecycle support.

Supply support for CY74FCT2244TQC 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 for industrial, automotive, and communications markets.

The CY74FCT family was engineered to provide TTL-compatible speed and drive with CMOS-like power efficiency and enhanced noise immunity for high-reliability digital interface applications.

FAQ

What is the maximum operating temperature range for CY74FCT2244TQC?

CY74FCT2244TQC is specified for continuous operation from –40°C to +85°C ambient temperature. This industrial-grade range supports deployment in programmable logic controllers, motor drives, and outdoor communication equipment without derating. The device's thermal resistance (θ_JA = 68°C/W in QSOP) ensures safe junction temperatures under typical 20-mA dynamic loads at 85°C ambient.

Does CY74FCT2244TQC require external pull-up or pull-down resistors on its enable inputs?

No - CY74FCT2244TQC does not require external biasing on OEA or OEB. Its TTL-compatible inputs have defined thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V) and low input current (±1 µA), allowing direct connection to microcontroller GPIOs or open-collector drivers. Unused enables should be tied to V_CC or GND per TI's recommended operating conditions to prevent floating states.

Can CY74FCT2244TQC safely interface with 3.3-V logic inputs?

CY74FCT2244TQC outputs swing to VOH ≥ 2.4 V (at –15 mA) and VOL ≤ 0.55 V (at 12 mA) under 5-V supply, meeting 3.3-V logic high and low thresholds. However, its inputs are strictly TTL-level (not 3.3-V compatible) - applying 3.3-V signals directly may result in marginal VIH margin. For bidirectional 3.3-V/5-V interfacing, pair CY74FCT2244TQC with a dedicated level translator on input side.

How does the 25-Ω on-die resistor in CY74FCT2244TQC improve signal integrity?

The 25-Ω series resistor per output in CY74FCT2244TQC matches typical PCB trace impedance (50–75 Ω) in source-series termination configurations. This reduces signal reflections at the driver end, suppressing overshoot, undershoot, and ringing - especially on traces >5 cm. Measured data shows >8 dB reduction in 100–500 MHz spectral noise versus non-terminated equivalents like SN74F244N.

Is CY74FCT2244TQC pin-compatible with standard 74LS244 devices?

Yes - CY74FCT2244TQC uses identical pinout and function mapping to industry-standard 74LS244 and 74ALS244 in QSOP-20 (DBQ) package. It retains the same DA0–DA3/OA0–OA3 and DB0–DB3/OB0–OB3 signal ordering, dual OE control (OEA/OEB), and power/ground placement. This enables drop-in replacement without PCB modification, while adding 25-Ω termination and I_off benefits.