onsemi 74FR244SJX

Overview

74FR244SJX from Fairchild Semiconductor is a non-inverting octal buffer/line driver with 3-STATE outputs, designed for memory address driving, clock distribution, and bus-oriented transmitter/receiver functions. It operates from +4.5V to +5.5V, sinks up to 64 mA per output, sources 15 mA, and guarantees pin-to-pin skew ≤1.6 ns (HL transitions) in a 20-lead SOP package.

For engineers reviewing the 74FR244SJX datasheet, pinout, applications, or equivalent options, key selection criteria include 3-STATE timing (tPZH ≤6.6 ns), DC drive capability (IOL = 64 mA), input voltage thresholds (VIH = 2.0 V, VIL = 0.8 V), and JEDEC-compliant SOP-20 (M20D) packaging.

Technical Context

The 74FR244SJX implements dual 4-bit non-inverting buffers controlled by two independent active-low output enables (OE1, OE2), each gating four outputs (O0–O3 and O4–O7). All outputs enter high-impedance state when respective OE is HIGH.

It uses bipolar Schottky-clamped logic for TTL-compatible input thresholds and fast propagation (tPLH/tPHL ≤3.9 ns at CL = 50 pF), with guaranteed skew performance critical for synchronous bus timing integrity across all eight outputs.

Key Specifications

Pinout & Package

74FR244SJX is housed in a 20-lead Small Outline Package (SOP), EIAJ TYPE II, 5.3 mm wide (Package Number M20D), with gull-wing leads and standard JEDEC pinout spacing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74F244SCX and SN74LS244N, the 74FR244SJX uniquely balances high sink current (64 mA), guaranteed skew (≤1.6 ns), and SOP-20 packaging-making it optimal for space-constrained, noise-sensitive, multi-drop bus applications where timing correlation matters more than peak speed.

Availability

74FR244SJX is available at Aetrix Electronics and suitable for memory address buffering, clock distribution, parallel bus interfacing, and legacy peripheral expansion requiring stable component supply and long-term industrial availability.

Supply support for 74FR244SJX 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in analog and discrete power products, acquired by ON Semiconductor in 2016.

The 74FR244SJX belongs to Fairchild's FAST TTL (Fairchild Advanced Schottky TTL) family, engineered for high-speed, low-skew bus interface applications in industrial and computing systems.

FAQ

What is the operating voltage range for the 74FR244SJX?

The 74FR244SJX operates from +4.5V to +5.5V. This range ensures reliable compatibility with standard 5V TTL logic systems and accommodates typical power supply tolerances. Operation outside this range may cause functional failure or permanent damage, as specified in the Absolute Maximum Ratings table of the Fairchild datasheet DS010900.

Does the 74FR244SJX support true bidirectional data flow?

No, the 74FR244SJX is a non-inverting octal buffer only - it does not contain internal direction control or transceiver logic. Data flows unidirectionally from inputs (I0–I7) to outputs (O0–O7). Bidirectional operation requires external control of the two active-low output enables (–OE1, –OE2) and complementary drivers on the same bus, as implemented in system-level design.

What is the meaning of "guaranteed pin-to-pin skew" for the 74FR244SJX?

Guaranteed pin-to-pin skew means the absolute timing difference between any two output transitions (e.g., O0 and O7 going HIGH-to-LOW) is bounded at ≤1.6 ns for HL transitions. This specification is measured under defined conditions (VCC = 5.0V, TA = 0°C to +70°C, CL = 50 pF) and ensures deterministic bus timing critical for synchronous memory or clock distribution.

Can the 74FR244SJX be used with 3.3V logic systems?

The 74FR244SJX is not 3.3V-tolerant: its minimum VCC is +4.5V, and inputs are TTL-compatible (VIH = 2.0V), not 3.3V CMOS-compatible. Direct connection to 3.3V logic risks undriven inputs or excessive current due to VIH mismatch. Level-shifting circuitry or a 3.3V-compatible alternative (e.g., 74LVC244A) is required for mixed-voltage systems.

What package type does the 74FR244SJX use, and is it RoHS compliant?

The 74FR244SJX uses a 20-lead Small Outline Package (SOP), EIAJ TYPE II, 5.3 mm wide (Package Number M20D). As a device introduced prior to 2006 and discontinued before RoHS enforcement, it is not RoHS compliant. For new designs requiring RoHS compliance, consult Aetrix Electronics for qualified drop-in alternatives with equivalent timing and drive specs.