My Inquiry
My Account
Texas Instruments SN74ALS244CNSR
- Part No.:
- SN74ALS244CNSR
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.209", 5.30mm Width)
- Datasheet:
-
SN74ALS244CNSR.pdf
- Description:
- IC BUFFER NON-INVERT 5.5V 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,117
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74ALS244CNSR 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 ±12 mA output drive, supports 0°C to 70°C ambient, and features pnp input structure to reduce DC loading on upstream logic.
For engineers reviewing the SN74ALS244CNSR datasheet, SN74ALS244CNSR pinout, SN74ALS244CNSR application, or SN74ALS244CNSR equivalent, this page provides verified functional specifications, SOP-20 package details, timing characteristics (e.g., tPLH ≤ 10 ns), thermal limits, and direct alternatives for legacy TTL bus interface designs.
Technical Context
The SN74ALS244CNSR implements two independent 4-bit groups (1A–1Y and 2A–2Y), each controlled by a dedicated active-low 3-state enable (1OE, 2OE). Its ALS (Advanced Low-Power Schottky) architecture delivers higher speed and lower power than standard LS TTL while maintaining pin- and logic-compatibility.
Input thresholds are VIH = 2.0 V (min), VIL = 0.8 V (max); output levels meet VOH ≥ 2.4 V at IOH = –12 mA and VOL ≤ 0.4 V at IOL = 12 mA. Propagation delays are asymmetric: tPLH = 2–10 ns, tPHL = 3–10 ns, with enable/disable times up to 26 ns.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL rails; absolute max 7 V. |
| Operating Temperature | 0°C to 70°C - commercial-grade rating; not rated for extended industrial or military ranges. |
| Output Drive (IOL) | 12 mA (standard), 24 mA (max) - sufficient to drive 10 LS-TTL loads or short PCB traces without buffering. |
| Propagation Delay | tPLH ≤ 10 ns, tPHL ≤ 10 ns (VCC = 4.5–5.5 V, CL = 50 pF) - enables reliable operation in sub-100 MHz address/data bus systems. |
| 3-State Enable Time | tPZL ≤ 20 ns, tPHZ ≤ 10 ns - ensures fast bus release and clean contention-free switching between drivers. |
| Input Loading | pnp input structure - reduces DC input current to ≤ 0.1 mA, minimizing loading on preceding gate outputs. |
| Package | SOP-20 (NS) - 0.635 mm pitch, 7.5 mm × 12.8 mm body, RoHS-compliant NIPDAU finish, MSL Level-1. |
Pinout & Package
SOP-20 (NS) package: 20-pin surface-mount small-outline plastic package with 0.635 mm lead pitch, 2.0 mm max height, and pin 1 quadrant Q1 orientation per TI tape-and-reel specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Group 1 Output Enable (active low) | Disables Y1–Y4 outputs when high; enables when low - used for bus arbitration or group-select control. |
| 1A1–1A4 | Group 1 Input Signals | Non-inverting inputs driving Y1–Y4; electrically isolated from Group 2 for dual-bus isolation. |
| 1Y1–1Y4 | Group 1 Output Signals | 3-state buffered outputs mirroring A1–A4; high-impedance when 1OE = high. |
| GND (Pin 10) | Ground Reference | Primary signal return path; must be low-inductance connection to minimize ground bounce in bus switching. |
| VCC (Pin 20) | Power Supply | +5 V supply rail; requires local 0.1 µF ceramic decoupling adjacent to pin. |
| 2OE | Group 2 Output Enable (active low) | Independent control of Y5–Y8; enables concurrent or staggered bus access with Group 1. |
| 2A1–2A4 | Group 2 Input Signals | Second set of four inputs; allows full octal buffering without external gating logic. |
| 2Y1–2Y4 | Group 2 Output Signals | Outputs Y5–Y8 (pins 19, 17, 15, 13); identical electrical behavior to Y1–Y4. |
Key Features
| Feature | Design Value |
|---|---|
| Octal 3-state non-inverting buffers | Two independent 4-bit groups simplify address/data bus fan-out without external logic. |
| pnp input structure | Reduces input current to ≤ 0.1 mA, lowering loading on upstream LS/ALS gates and improving noise margin. |
| ALS process technology | Delivers 2× speed and 50% lower power vs. standard LS TTL at same voltage - critical for dense backplane designs. |
| Bus-oriented timing | Matched tPLH/tPHL and fast enable/disable ensure glitch-free bus handoff in multi-driver systems. |
| SOP-20 RoHS-compliant packaging | Enables automated SMT assembly; MSL Level-1 allows unlimited floor life before reflow. |
Applications
| Memory Address Buffering | Parallel Bus Transceiver Interface |
|---|---|
|
Use Scenario: Driving 16-bit address lines from a microprocessor to multiple memory ICs on a shared bus. IC Role / Device Role / Timing Role: Non-inverting buffer with 3-state outputs isolates CPU address bus during DMA or peripheral access. Use Value: Prevents bus contention via independent OE controls; 10 ns propagation supports >10 MHz CPU address strobes. |
Use Scenario: Bidirectional data bus isolation between two processor subsystems sharing a common data path. IC Role / Device Role / Timing Role: Dual-group 3-state driver enables direction-controlled data flow without external transceivers. Use Value: Eliminates need for separate direction-control logic; matched tPZL/tPHZ ensures <20 ns bus turnaround. |
| Clock Distribution Network | Legacy TTL System Expansion |
|
Use Scenario: Distributing a system clock to multiple synchronous peripherals (e.g., UARTs, timers) with minimal skew. IC Role / Device Role / Timing Role: Low-skew, high-drive buffer replicating clock signal across PCB traces. Use Value: ±12 mA drive sustains signal integrity over 10 cm FR-4 traces; ALS speed avoids clock jitter accumulation. |
Use Scenario: Upgrading vintage industrial controllers using 74LS244-based logic with improved reliability and supply tolerance. IC Role / Device Role / Timing Role: Pin- and function-compatible drop-in replacement for LS244 in existing layouts. Use Value: Same pinout and logic behavior, but wider VCC range (4.5–5.5 V) and lower power dissipation improve field longevity. |
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 |
|---|---|---|---|
| SN74AS244ANSR | Faster propagation (tPLH ≤ 6.2 ns), higher drive (IOL = 48 mA), AS process - consumes ~2.5× more ICC than ALS. | Better suited for high-speed bus arbitration where timing margin is critical; less suitable for low-power legacy upgrades. | Select SN74AS244ANSR only if sub-7 ns delay is required and power budget allows +30 mA typical ICC. |
| SN74HC244N | CMOS technology, 2–6 V supply, lower IOL (±7.8 mA), slower at 5 V (tPLH ≈ 25 ns), no pnp inputs. | Compatible with mixed-voltage systems but lacks TTL input thresholds and cannot directly replace ALS in 5 V-only buses. | Choose SN74HC244N only when migrating to wide-supply designs or when ultra-low static power (<1 µA) is mandatory. |
Compared with SN74ALS244CNSR, SN74AS244ANSR trades higher speed and drive for increased power consumption, while SN74HC244N offers supply flexibility and low quiescent current at the cost of speed and TTL-level compatibility - making SN74ALS244CNSR optimal for stable 5 V legacy bus interfaces requiring proven reliability and balanced performance.
Availability
SN74ALS244CNSR is available at Aetrix Electronics and suitable for memory address buffering, parallel bus interfacing, clock distribution, and legacy TTL system upgrades requiring stable component supply and long-term obsolescence management.
Supply support for SN74ALS244CNSR 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 founded in 1930, specializing in analog, embedded processing, and logic solutions with deep heritage in TTL and advanced logic families.
The SN74ALS244CNSR belongs to TI's Advanced Low-Power Schottky (ALS) logic series, engineered for high-density, high-speed bus interface applications in industrial control, test equipment, and legacy computing systems.
FAQ
What is the maximum operating temperature range for the SN74ALS244CNSR?
The SN74ALS244CNSR is rated for commercial operation from 0°C to 70°C ambient temperature. It is not characterized for extended industrial (–40°C to 85°C) or military (–55°C to 125°C) ranges - those require SN54ALS244C variants in ceramic packages.
Does the SN74ALS244CNSR support true bidirectional data transfer?
No - the SN74ALS244CNSR is a unidirectional octal buffer with non-inverting inputs and 3-state outputs. For bidirectional operation, two SN74ALS244CNSR devices must be used in opposing directions with coordinated OE control, or a dedicated transceiver like SN74LS245 should be selected.
What is the recommended decoupling for SN74ALS244CNSR in high-speed applications?
TI recommends a 0.1 µF ceramic capacitor placed as close as possible to the VCC (Pin 20) and GND (Pin 10) pins of the SN74ALS244CNSR. For systems with multiple devices, add a bulk 4.7 µF tantalum or aluminum electrolytic capacitor near the board's 5 V supply entry point.
Can SN74ALS244CNSR be used as a direct replacement for SN74LS244N in existing designs?
Yes - the SN74ALS244CNSR is functionally and pin-compatible with SN74LS244, offering improved speed (≈2× faster), lower power, and tighter VIL/VIH thresholds. No PCB changes are required, though verify that the SOP-20 footprint matches the original DIP-20 layout - adapter may be needed for through-hole boards.
What does the "-1" suffix mean in variants like SN74ALS244C-1NSR?
The "-1" suffix denotes a version qualified for higher output sink current: IOL = 48 mA (vs. 12 mA standard), but only under strict conditions - VCC between 4.75 V and 5.25 V and TA = 25°C. The SN74ALS244CNSR is the standard version, not the -1 variant.
SN74ALS244CNSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74ALS
- Package/Case:
- 20-SOIC (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- Surface Mount
- Supplier Device Package:
- 20-SO
SN74ALS244CNSR FAQ
1.How can I place an order for SN74ALS244CNSR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74ALS244CNSR 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 SN74ALS244CNSR reliable?
The price and inventory of SN74ALS244CNSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74ALS244CNSR is usually 5 days.
3.What payment methods are accepted for SN74ALS244CNSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74ALS244CNSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74ALS244CNSR?
SN74ALS244CNSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74ALS244CNSR 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 SN74ALS244CNSR?
For technical support, including SN74ALS244CNSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74ALS244CNSR requirements.
6.How does Aetrix verify that SN74ALS244CNSR is sourced from the original manufacturer or authorized distributors?
All SN74ALS244CNSR 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 SN74ALS244CNSR meets industry standards.
7.What is the process for return or replacement of SN74ALS244CNSR?
All SN74ALS244CNSR units undergo pre-shipment inspection (PSI). If there is an issue with SN74ALS244CNSR, 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 SN74ALS244CNSR part is unused and in its original packaging.
Return procedure for SN74ALS244CNSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74ALS244CNSR 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…
