My Inquiry
My Account
Texas Instruments SN74ALS244CN
- Part No.:
- SN74ALS244CN
- Manufacturer:
- Texas Instruments
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
SN74ALS244CN.pdf
- Description:
- IC BUF NON-INVERT 5.5V 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:359
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ALS244CN from Texas Instruments is an octal non-inverting buffer/line driver with 3-state outputs, designed for memory address driving, bus interfacing, and clock distribution in TTL-compatible systems. It operates from 4.5 V to 5.5 V, delivers ±24 mA output drive, supports 0°C to 70°C industrial temperature range, and features pnp input structure for reduced DC loading - used in legacy industrial control backplanes and ISA-bus peripheral interfaces.
For engineers reviewing the SN74ALS244CN datasheet, SN74ALS244CN pinout, SN74ALS244CN application, or SN74ALS244CN equivalent, key selection criteria include 3-state bus contention management, TTL-level compatibility, 10 ns typical propagation delay, IOL=24 mA drive capability at VCC=5 V, and PDIP-20 package suitability for through-hole prototyping and repair.
Technical Context
This device implements two independent 4-bit non-inverting buffer groups (1A→1Y and 2A→2Y), each controlled by a dedicated active-low 3-state enable input (1OE, 2OE). The pnp input stage minimizes input current draw, improving fan-out in dense TTL bus environments.
Output switching follows standard TTL voltage thresholds: VIH ≥ 2.0 V, VIL ≤ 0.8 V; VOH ≥ 2.4 V at IOH = –12 mA; VOL ≤ 0.4 V at IOL = 24 mA. Enable-to-output timing (tPZL/tPHZ) is specified at ≤20 ns, ensuring reliable bus arbitration in synchronous memory subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | ALS (Advanced Low-Power Schottky) TTL - balances speed (10 ns tPLH) and power (24 mA ICC max) vs standard LS. |
| Supply Voltage | 4.5 V to 5.5 V - compatible with regulated 5 V rails; absolute max 7 V prevents damage during transient overvoltage. |
| Output Drive | IOL = 24 mA / IOH = –12 mA - sufficient to drive 10+ standard TTL loads or terminate short stubs on parallel buses. |
| Propagation Delay | tPLH/tPHL ≤ 10 ns @ CL = 50 pF - enables operation in sub-100 MHz bus cycles with margin. |
| Operating Temp | 0°C to 70°C - qualified for commercial/industrial equipment, not extended or military grade. |
| 3-State Enable | Active-low OE inputs (1OE, 2OE) - allows independent control of each 4-bit group for bidirectional bus partitioning. |
| Input Structure | pnp-based inputs - reduces IIH/IIL to ≤20 µA/–0.1 mA, lowering system-level DC loading on upstream drivers. |
Pinout & Package
SN74ALS244CN uses a 20-pin plastic dual in-line package (PDIP-N), 300-mil width, with standard through-hole footprint and 2.54 mm pitch. Pin 1 is located at top-left corner with notch or dot marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Group 1 Output Enable (active low) | Disables Y1–Y4 outputs to high-impedance when logic high; enables buffering when low. |
| 1A1–1A4 | Group 1 Input Signals | Non-inverting inputs for first 4-bit buffer channel; TTL-compatible voltage thresholds. |
| 1Y1–1Y4 | Group 1 Output Signals | 3-state buffered outputs corresponding to 1A1–1A4; driven only when 1OE = low. |
| GND | Ground Reference | Pin 10 - primary signal return path; decoupling capacitor must be placed adjacent to this pin. |
| VCC | Power Supply | Pin 20 - +5 V supply; requires local 0.1 µF ceramic bypass capacitor between Pins 20 and 10. |
| 2OE | Group 2 Output Enable (active low) | Independent control of second 4-bit group; enables/disables Y5–Y8 (labeled 2Y1–2Y4). |
| 2A1–2A4 | Group 2 Input Signals | Inputs for second buffer bank; electrically identical to 1A1–1A4 but isolated internally. |
| 2Y1–2Y4 | Group 2 Output Signals | Outputs labeled as 2Y1–2Y4 on datasheet; correspond to pins 19, 17, 15, 13 respectively. |
Key Features
| Feature | Design Value |
|---|---|
| Octal 3-State Buffer Architecture | Two independent 4-bit groups with separate OE controls - enables flexible bus segmentation without external logic. |
| pnp Input Stage | Reduces input current to ≤20 µA (IIH) and –0.1 mA (IIL) - increases effective fan-out in cascaded TTL designs. |
| TTL-Compatible Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - ensures interoperability with 74LS, 74F, and legacy microprocessor buses. |
| High Sink Current Capability | IOL = 24 mA per output - drives heavy capacitive loads (e.g., >100 pF) or multiple TTL inputs without level-shifting. |
| Low Propagation Delay | tPLH/tPHL ≤ 10 ns @ CL = 50 pF - supports fast address/data strobing in 80286/80386-era embedded controllers. |
Applications
| Memory Address Buffering | ISA Bus Peripheral Interface |
|---|---|
Use Scenario: Driving 20-bit address bus from microcontroller to multiple memory chips in industrial PLC backplane. IC Role / Device Role / Timing Role: Non-inverting buffer isolating CPU address lines while enabling/disabling segments via 1OE and 2OE. Use Value: Prevents bus contention during DMA cycles; 24 mA sink current ensures clean edges across 15 cm PCB traces. | Use Scenario: Interfacing custom I/O card to ISA bus slot in legacy test equipment. IC Role / Device Role / Timing Role: Bidirectional data/address line driver with 3-state control synchronized to ISA IOR/IOW strobes. Use Value: Enables hot-plug compatible isolation; pnp inputs reduce loading on ISA bus drivers during idle states. |
| Legacy Clock Distribution | Industrial Control Backplane |
Use Scenario: Distributing 8 MHz system clock to multiple synchronous peripherals in CNC motion controller. IC Role / Device Role / Timing Role: Low-skew clock buffer with independent enable for selective peripheral clock gating. Use Value: 10 ns max tPLH ensures <1% duty-cycle distortion across 8 outputs; TTL thresholds match oscillator IC outputs. | Use Scenario: Signal conditioning and level translation between 5 V microcontrollers and 24 V discrete I/O modules. IC Role / Device Role / Timing Role: Logic-level translator and noise-immune bus repeater in electrically noisy factory environments. Use Value: High noise margin (VNH ≈ 0.7 V, VNL ≈ 0.4 V) rejects EMI-induced glitches on long ribbon cables. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal 3-state buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ALS244C-1N | Same ALS family, but -1 version rated for IOL = 48 mA at VCC = 4.75–5.25 V; otherwise identical pinout and logic. | Required where higher sink current is needed for driving >15 TTL loads or longer transmission lines. | Select SN74ALS244C-1N only if verified load demands exceed 24 mA per output; SN74ALS244CN suffices for standard bus loading. |
| SN74AS244AN | AS family: faster (tPLH ≤ 6.2 ns), higher drive (IOL = 48 mA), but higher ICC (60 mA vs 24 mA); same PDIP-20 package. | Suitable for high-speed timing-critical paths but increases power and heat in thermally constrained enclosures. | Choose SN74AS244AN only when propagation delay <7 ns is mandatory; SN74ALS244CN offers better power efficiency for general-purpose buffering. |
Compared with SN74ALS244C-1N and SN74AS244AN, SN74ALS244CN provides optimal balance of speed (10 ns), drive strength (24 mA), and quiescent current (24 mA ICC) for cost-sensitive industrial control applications where extreme performance is unnecessary.
Availability
SN74ALS244CN is available at Aetrix Electronics and suitable for memory address buffering, ISA bus peripheral interfacing, and legacy clock distribution requiring stable component supply across long-lifecycle industrial programs.
Supply support for SN74ALS244CN 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs with broad industrial and automotive qualification.
The SN74ALS244CN belongs to TI's legacy 74ALS logic family, engineered for high-speed, low-power TTL-compatible interfacing in industrial control, instrumentation, and retro-computing systems.
FAQ
What is the maximum operating temperature range for SN74ALS244CN?
The SN74ALS244CN is characterized for operation from 0°C to 70°C, making it suitable for commercial and industrial ambient environments but not extended temperature or military-grade applications. This range is explicitly defined in the recommended operating conditions table of the SDAS142C datasheet, and thermal derating is not supported beyond these limits.
Does SN74ALS244CN support true bidirectional data flow?
No, SN74ALS244CN is a unidirectional non-inverting buffer - signals flow only from A inputs to Y outputs. True bidirectional operation requires external control logic or a transceiver like SN74LS245. The 3-state outputs allow bus sharing but do not reverse signal direction.
Can SN74ALS244CN be used with 3.3 V logic systems?
SN74ALS244CN is not 3.3 V tolerant: its minimum VCC is 4.5 V, and VIH threshold is 2.0 V - insufficient for reliable recognition of 3.3 V logic highs. Direct interface risks undefined behavior; level-shifting circuitry or a 3.3 V–compatible buffer (e.g., SN74LVC244A) is required.
What is the purpose of the pnp input structure in SN74ALS244CN?
The pnp input structure in SN74ALS244CN reduces input current draw - IIH ≤ 20 µA and IIL ≤ –0.1 mA - minimizing loading on upstream drivers and increasing effective fan-out in multi-load TTL bus configurations. This design choice directly improves signal integrity in daisy-chained address/data paths.
Is SN74ALS244CN pin-compatible with SN74LS244N?
Yes, SN74ALS244CN is pin-compatible and functionally equivalent to SN74LS244N in PDIP-20 packaging, sharing identical pinout, logic behavior, and 3-state control. However, SN74ALS244CN offers faster propagation delay (10 ns vs 15 ns) and lower power consumption, making it a direct performance upgrade within the same footprint.
SN74ALS244CN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Active
- 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, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
SN74ALS244CN FAQ
1.How can I place an order for SN74ALS244CN through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS244CN 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 SN74ALS244CN reliable?
The price and inventory of SN74ALS244CN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS244CN is usually 5 days.
3.What payment methods are accepted for SN74ALS244CN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS244CN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS244CN?
SN74ALS244CN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS244CN 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 SN74ALS244CN?
For technical support, including SN74ALS244CN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS244CN requirements.
6.How does Aetrix verify that SN74ALS244CN is sourced from the original manufacturer or authorized distributors?
All SN74ALS244CN 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 SN74ALS244CN meets industry standards.
7.What is the process for return or replacement of SN74ALS244CN?
All SN74ALS244CN units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS244CN, 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 SN74ALS244CN part is unused and in its original packaging.
Return procedure for SN74ALS244CN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ALS244CN 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
