My Inquiry
My Account
onsemi 74FR244SCX
- Part No.:
- 74FR244SCX
- Manufacturer:
- onsemi
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
74FR244SCX.pdf
- Description:
- IC BUF NON-INVERT 5.5V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,725
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74FR244SCX 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 of ≤1.6 ns (HL) and ≤1.0 ns (LH).
For engineers reviewing the 74FR244SCX datasheet, pinout, applications, or equivalent options, key selection criteria include 3-STATE timing (tPZH ≤ 6.6 ns), output drive strength (64 mA sink), input voltage thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V), and SOIC-20 package compatibility with JEDEC MS-013.
Technical Context
The 74FR244SCX implements dual 4-bit non-inverting buffers controlled by two independent active-low enable inputs (OE1, OE2), each enabling four outputs. Its TTL-compatible inputs accept 0.8 V/2.0 V logic thresholds and feature ±150 µA low-level / 5 µA high-level input current.
Outputs switch with propagation delays as low as 1.0 ns (tPLH/tPHL, CL = 50 pF), support 3-STATE transitions in ≤6.6 ns (enable time), and maintain guaranteed skew across all eight outputs-critical for synchronized bus driving in memory and address path applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | +4.5 V to +5.5 V - ensures compatibility with standard 5 V TTL/CMOS systems |
| Output Sink Current | 64 mA - drives heavy capacitive loads or multiple TTL inputs without external buffering |
| Output Source Current | 15 mA - sufficient for driving CMOS inputs or light loads in active-HIGH mode |
| Propagation Delay | 1.0–3.9 ns (CL = 50 pF) - enables high-speed address/data bus operation up to ~250 MHz effective toggle rate |
| Input Thresholds | VIH ≥ 2.0 V, VIL ≤ 0.8 V - provides robust noise margin against TTL logic levels |
| Pin-to-Pin Skew | tOSLH ≤ 1.0 ns, tOSHL ≤ 1.6 ns - ensures simultaneous edge alignment across all eight outputs for clean bus settling |
Pinout & Package
74FR244SCX is housed in a 20-lead Small Outline Integrated Circuit (SOIC) package, JEDEC MS-013 compliant, 0.300" wide, with gull-wing leads and standard pitch (1.27 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | O0, O7 | Non-inverting buffered outputs - driven when respective OE is LOW |
| 2, 18 | I0, I7 | Buffer inputs - pass through to corresponding outputs when enabled |
| 3, 5, 7, 9 | –OE2 | Active-low enable for outputs O0–O3 - asserts 3-STATE when HIGH |
| 12, 14, 16, 18 | –OE1 | Active-low enable for outputs O4–O7 - independent control group |
| 10, 20 | GND, VCC | Power supply reference and positive rail - decoupling required near pin 20 |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit enables | Separate –OE1 (pins 12,14,16,18) and –OE2 (pins 3,5,7,9) allow partitioned bus control without external logic |
| Guaranteed pin-to-pin skew | tOSLH ≤ 1.0 ns ensures deterministic timing alignment across all eight outputs for synchronous bus interfaces |
| High-output drive capability | 64 mA sink per output supports direct connection to 10+ TTL loads or long PCB traces with minimal signal degradation |
| 3-STATE output disable timing | tPHZ/tPLZ ≤ 6.4 ns guarantees fast bus release, reducing contention windows in shared-data-path systems |
Applications
| Memory Address Buffering | Clock Distribution Network |
|---|---|
Use Scenario: Driving 16-bit address bus from microcontroller to SRAM or EPROM with fanout >8. IC Role / Device Role / Timing Role: Non-inverting octal buffer isolating CPU address lines while providing current gain and skew-controlled timing. Use Value: Eliminates need for discrete transistor arrays; 64 mA sink ensures full logic swing across 100+ pF trace capacitance. | Use Scenario: Distributing a single system clock to multiple peripheral ICs with matched edge timing. IC Role / Device Role / Timing Role: Low-skew line driver replicating clock signal to four downstream devices via O0–O3 (–OE2 enabled). Use Value: ≤1.0 ns LH skew prevents setup/hold violations across clocked peripherals operating at >100 MHz. |
| Bi-directional Bus Transceiver Interface | Legacy System Address Latching |
Use Scenario: Isolating data/address buses between processor and FPGA-based co-processor during read/write cycles. IC Role / Device Role / Timing Role: 3-STATE-enabled buffer acting as direction-controlled bus gate, with OE1/OE2 toggled by control logic. Use Value: Fast 3-STATE enable/disable (tPZH ≤ 6.6 ns) minimizes bus turnaround latency in burst-mode transfers. | Use Scenario: Latching 8-bit I/O port addresses in industrial PLC backplane with legacy 8085/8086 architecture. IC Role / Device Role / Timing Role: Octal buffer holding stable address bits during memory access cycles while CPU executes internal operations. Use Value: Guaranteed 3.9 ns max propagation delay meets 4 MHz bus timing budgets with margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal buffer/line driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74ACT244SCX | Higher speed (tPLH/tPHL ≤ 2.5 ns), 3-STATE current limited to 24 mA sink, TTL-compatible but ACT-family VCC = 4.5–5.5 V | Better for <5 ns timing-critical paths; lower drive limits require verification under 64 mA load conditions | Select when propagation delay is prioritized over output current capability |
| SN74LVC244APWR | 3.3 V only (1.65–3.6 V), 24 mA sink, 32 mA source, 3-STATE leakage <10 µA, smaller TSSOP-20 package | Not voltage-compatible with 5 V systems; requires level-shifting if interfacing with legacy 5 V logic | Select for modern 3.3 V embedded designs where power efficiency and board space outweigh 5 V interoperability |
Compared with 74FR244SCX, the 74ACT244SCX trades higher drive strength for faster switching, while the SN74LVC244APWR shifts to 3.3 V operation with reduced power and footprint-neither is pin-compatible without voltage or layout adaptation.
Availability
74FR244SCX is available at Aetrix Electronics and suitable for memory subsystem design, clock distribution networks, and legacy bus interface applications requiring stable component supply and long-term industrial availability.
Supply support for 74FR244SCX 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 mixed-signal ICs, power management, and logic devices before its acquisition by ON Semiconductor in 2016.
The 74FR244SCX belongs to Fairchild's FAST TTL-compatible logic family, engineered for high-speed, low-skew bus interfacing in industrial and computing systems operating at 5 V.
FAQ
What is the maximum operating temperature range for the 74FR244SCX?
The 74FR244SCX is rated for ambient temperature under bias from 0°C to +70°C, with junction temperature up to +150°C. It is intended for commercial-grade applications and not specified for extended industrial or automotive temperature ranges. Derating is required above +70°C ambient to maintain reliability.
Does the 74FR244SCX support 3.3 V logic inputs?
No, the 74FR244SCX does not guarantee reliable operation with 3.3 V logic inputs. Its input thresholds are defined for 5 V TTL systems (VIH ≥ 2.0 V, VIL ≤ 0.8 V), and applying 3.3 V signals may result in marginal or undefined switching behavior. For 3.3 V systems, consider the SN74LVC244APWR instead of the 74FR244SCX.
Is the 74FR244SCX pin-compatible with the 74F244 or 74LS244?
The 74FR244SCX shares identical pinout and function with the 74F244 and 74LS244 in SOIC-20 (M20B) packaging, including OE1/OE2 placement and I/O mapping. However, electrical characteristics differ-especially output drive and AC timing-so direct substitution requires validation of timing margins and load conditions in the target circuit.
What is the purpose of the two separate output enable inputs (–OE1 and –OE2) on the 74FR244SCX?
The dual enable inputs (–OE1 on pins 12/14/16/18; –OE2 on pins 3/5/7/9) allow independent control of two groups of four outputs (O4–O7 and O0–O3). This enables selective bus segmentation-for example, enabling only upper address bits while holding lower bits in 3-STATE-without external gating logic, improving system-level timing control in the 74FR244SCX.
Can the 74FR244SCX be used in place of a 74HC244 in a 5 V design?
The 74FR244SCX is not a drop-in replacement for the 74HC244 due to differences in input structure (TTL vs. CMOS), output drive asymmetry (64 mA sink / 15 mA source vs. balanced HC), and AC timing. While both are octal buffers with 3-STATE, the 74FR244SCX exhibits faster propagation but higher ICCZ current; verify VIH/VIL compatibility and power budget before substituting the 74FR244SCX for 74HC244.
74FR244SCX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74FR
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Non-Inverting
- Number of Elements:
- 2
- Number of Bits per Element:
- 4
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 15mA, 64mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
74FR244SCX FAQ
1.How can I place an order for 74FR244SCX through Aetrix?
Please submit a Request for Quotation (RFQ) for 74FR244SCX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 74FR244SCX reliable?
The price and inventory of 74FR244SCX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74FR244SCX is usually 5 days.
3.What payment methods are accepted for 74FR244SCX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74FR244SCX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74FR244SCX?
74FR244SCX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74FR244SCX order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 74FR244SCX?
For technical support, including 74FR244SCX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74FR244SCX requirements.
6.How does Aetrix verify that 74FR244SCX is sourced from the original manufacturer or authorized distributors?
All 74FR244SCX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 74FR244SCX meets industry standards.
7.What is the process for return or replacement of 74FR244SCX?
All 74FR244SCX units undergo pre-shipment inspection (PSI). If there is an issue with 74FR244SCX, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 74FR244SCX part is unused and in its original packaging.
Return procedure for 74FR244SCX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74FR244SCX Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
