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Texas Instruments SN74HCT244PW
- Part No.:
- SN74HCT244PW
- Manufacturer:
- Texas Instruments
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74HCT244PW.pdf
- Description:
- IC BUF NON-INVERT 5.5V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,355
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Product details
Overview
SN74HCT244PW from Texas Instruments is an octal non-inverting 3-state buffer/line driver IC designed for bus-oriented memory address and clock signal buffering. It operates at 4.5–5.5 V, delivers ±6 mA output drive per channel, exhibits 13 ns typical propagation delay (at 5.5 V, 50 pF), and supports TTL-compatible inputs. It is used in server backplanes to isolate and strengthen address/data bus signals between CPU and memory modules.
For engineers reviewing the SN74HCT244PW datasheet, SN74HCT244PW pinout, SN74HCT244PW application, or SN74HCT244PW equivalent, key selection criteria include its 20-pin TSSOP package, dual 4-bit independent enable control, high-impedance 3-state outputs for bus sharing, and guaranteed operation across –40°C to +85°C ambient temperature.
Technical Context
The SN74HCT244PW implements two independent 4-bit buffer sections, each with dedicated active-low output-enable (1OE, 2OE) inputs. When OE is low, A→Y data passes non-inverted; when OE is high, all eight Y outputs enter high-impedance state-enabling bidirectional bus arbitration without contention.
It uses HCMOS technology with TTL-voltage compatible inputs (VIH = 2 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V), consumes ≤80 µA ICC (max), and drives up to 15 LSTTL loads. Its logic-level translation capability allows interfacing between 5 V TTL and CMOS systems while maintaining noise immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5 V logic rails and tolerates ±10% regulation variation. |
| Propagation delay (tpd) | 13 ns typical at VCC = 5.5 V, CL = 50 pF - enables reliable timing in high-speed address/data latching up to ~30 MHz bus rates. |
| Output drive | ±6 mA per output at VCC = 5 V - sufficient to directly drive 15 LSTTL inputs without external buffers. |
| Input compatibility | TTL-voltage compatible (VIH ≥ 2 V, VIL ≤ 0.8 V) - allows direct connection to legacy 5 V TTL outputs without level shifters. |
| Quiescent current (ICC) | ≤80 µA maximum - minimizes static power in always-on bus interface stages of industrial controllers. |
| Operating temperature | –40°C to +85°C - qualified for commercial and extended-temperature embedded applications including telecom infrastructure. |
| ESD rating (HBM) | ±2000 V - meets JEDEC JS-001 Class 2, supporting robust handling in automated PCB assembly lines. |
Pinout & Package
TSSOP-20 (PW) package: 6.5 mm × 6.4 mm body size, 0.65 mm lead pitch, thin-profile surface-mount construction optimized for high-density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1OE, 2OE | Active-low output-enable controls for Group 1 (pins 2–9) and Group 2 (pins 11–18); asserted low enables buffer pass-through. |
| 2–5, 11–14 | A1–A4 (Group 1 & 2) | Non-inverting input terminals; accept TTL/CMOS logic levels and drive corresponding Y outputs when OE is active. |
| 3, 5, 7, 9, 12, 14, 16, 18 | Y1–Y4 (Group 1 & 2) | 3-state buffered outputs; high-impedance when OE = high, otherwise replicate A inputs with ±6 mA drive capability. |
| 10 | GND | Ground reference for all logic and output circuitry; must be low-impedance connection to minimize noise coupling. |
| 20 | VCC | Positive supply rail (4.5–5.5 V); requires local 0.1 µF ceramic bypass capacitor placed adjacent to pin for stable switching operation. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit buffering | Enables selective isolation of two bus segments (e.g., CPU address vs. peripheral I/O) using separate OE controls. |
| 3-state outputs with fast enable/disable | ten/tdis ≤ 25 ns (typical at 5.5 V) - ensures clean bus turn-around with minimal contention window in shared-memory systems. |
| TTL-compatible inputs | Accepts standard 5 V TTL logic thresholds without external biasing - simplifies integration with legacy microcontrollers and FPGAs. |
| Low quiescent power | ICC ≤ 80 µA max - reduces standby power in always-powered network switch control planes and LED display drivers. |
| High noise immunity | VIH/VIL margins of 1.2 V/0.2 V at VCC = 5 V - suppresses false triggering from EMI in motor driver gate-drive interface circuits. |
Applications
| Server Memory Interface | LED Display Column Driver |
|---|---|
|
Use Scenario: Buffering and isolating CPU-generated memory address signals before routing to DRAM modules on a multi-layer server motherboard. IC Role / Device Role / Timing Role: Non-inverting 3-state buffer that strengthens address bus drive strength and prevents loading-induced timing skew across 16-bit wide traces. Use Value: Enables reliable 100+ MHz address strobing by delivering ±6 mA per line and maintaining <13 ns tpd across all eight channels. |
Use Scenario: Driving column lines of a 16×32 multiplexed LED matrix in industrial panel displays where brightness uniformity and scan rate stability are critical. IC Role / Device Role / Timing Role: High-current line driver translating MCU GPIO outputs into sink-capable column currents for common-anode LED arrays. Use Value: Delivers consistent 6 mA per output across temperature, eliminating brightness drift during extended operation in ambient temperatures up to +85°C. |
| Network Switch Backplane | Industrial I/O Expander Interface |
|
Use Scenario: Interfacing FPGA-based packet forwarding logic to ASIC-based PHY layer controllers via shared control/status buses in 10G Ethernet switches. IC Role / Device Role / Timing Role: Bidirectional bus buffer enabling time-multiplexed read/write access to configuration registers without bus contention. Use Value: Fast 3-state transition (≤25 ns enable/disable) ensures sub-ns bus turnaround, supporting deterministic latency in real-time traffic scheduling. |
Use Scenario: Extending GPIO count of a PLC controller to manage 8-channel relay outputs and sensor inputs in factory automation cabinets. IC Role / Device Role / Timing Role: Level-translating buffer between 3.3 V MCU I/O and 5 V industrial field-side logic, providing noise-immune signal integrity. Use Value: TTL-compatible inputs tolerate 0.8–2.0 V noise margins, preventing spurious toggling in electrically noisy plant-floor environments. |
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 |
|---|---|---|---|
| SN74HCT244PWR | Same silicon die and electrical specs; differs only in packaging (TSSOP-20 tape-and-reel, not tube) and MSL rating (Level-1 vs obsolete PW tube variant). | Identical functional use in new designs; preferred for automated SMT assembly due to RoHS-compliant NIPDAU finish and full production status. | Select SN74HCT244PWR for volume manufacturing; SN74HCT244PW is obsolete and no longer recommended for new designs. |
| SN74LV244APWR | Lower-voltage variant (1.65–3.6 V operation); higher ICC (100 µA max); reduced output drive (±8 mA at 3.3 V); LV-CMOS input thresholds. | Suitable for mixed-voltage 3.3 V systems but incompatible with 5 V TTL inputs without level shifting; not drop-in replaceable. | Choose SN74LV244APWR only when migrating to 3.3 V core logic; retain SN74HCT244PW/PWR for 5 V legacy interoperability. |
Compared with SN74HCT244PWR, SN74HCT244PW shares identical electrical behavior but lacks current production support and tape-and-reel packaging-making PWR the de facto standard for new designs. SN74LV244APWR offers lower voltage operation but requires redesign for input threshold and supply compatibility.
Availability
SN74HCT244PW is available at Aetrix Electronics and suitable for server memory interfaces, LED display column driving, network switch backplanes, and industrial I/O expander applications requiring stable component supply and long-term obsolescence management.
Supply support for SN74HCT244PW 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 specializing in analog, embedded processing, and logic solutions, with over 50 years of innovation in high-reliability logic ICs.
The SN74HCT244PW belongs to TI's HCT logic family-designed specifically for 5 V TTL-to-CMOS interfacing in memory address, clock distribution, and bus transceiver applications where noise immunity and drive strength are critical.
FAQ
What is the operating temperature range for SN74HCT244PW?
The SN74HCT244PW is rated for operation from –40°C to +85°C ambient temperature. This range is validated per TI's production test conditions and supports deployment in commercial and extended-temperature industrial environments such as network switches and LED display enclosures. The SN74HCT244PW datasheet confirms this specification under Recommended Operating Conditions.
Is SN74HCT244PW pin-compatible with other SN74HCT244 package variants?
Yes, SN74HCT244PW is pin-compatible with all 20-pin SN74HCT244 variants-including DB (SSOP), DW (SOIC), NS (SOP), and DGS (VSSOP)-as they share identical pin numbering, function mapping, and electrical behavior. The SN74HCT244PW pinout matches the standard 20-pin layout defined in TI's SCLS175I datasheet Figure 4-1.
Does SN74HCT244PW support 3.3 V logic inputs?
No, SN74HCT244PW does not reliably support 3.3 V logic inputs. Its input thresholds are TTL-compatible (VIH ≥ 2.0 V, VIL ≤ 0.8 V at VCC = 4.5–5.5 V), meaning a 3.3 V high-level signal may fall below VIH margin under worst-case VCC and temperature conditions. For 3.3 V systems, SN74LV244APWR is the appropriate alternative.
What is the maximum capacitive load SN74HCT244PW can drive while maintaining specified tpd?
SN74HCT244PW maintains its specified 13 ns typical propagation delay (tpd) with a 50 pF load capacitance at VCC = 5.5 V. At 150 pF, tpd increases to 18 ns (typical). Exceeding 150 pF risks violating setup/hold timing in synchronous systems; TI recommends limiting trace + load capacitance to ≤100 pF for robust 25 MHz+ operation. This is documented in Section 5.8 of the SN74HCT244PW datasheet.
How should unused inputs be handled on SN74HCT244PW?
All unused inputs on SN74HCT244PW must be tied to either VCC or GND to prevent floating states that cause excessive ICC, oscillation, or undefined outputs. TI explicitly states this requirement in Section 8.4.1 of the SN74HCT244PW datasheet. Leaving inputs unconnected violates recommended operating conditions and may compromise device reliability in long-term operation.
SN74HCT244PW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Bulk
- 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:
- 6mA, 6mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
SN74HCT244PW FAQ
1.How can I place an order for SN74HCT244PW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HCT244PW 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 SN74HCT244PW reliable?
The price and inventory of SN74HCT244PW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HCT244PW is usually 5 days.
3.What payment methods are accepted for SN74HCT244PW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74HCT244PW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74HCT244PW?
SN74HCT244PW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74HCT244PW 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 SN74HCT244PW?
For technical support, including SN74HCT244PW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HCT244PW requirements.
6.How does Aetrix verify that SN74HCT244PW is sourced from the original manufacturer or authorized distributors?
All SN74HCT244PW 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 SN74HCT244PW meets industry standards.
7.What is the process for return or replacement of SN74HCT244PW?
All SN74HCT244PW units undergo pre-shipment inspection (PSI). If there is an issue with SN74HCT244PW, 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 SN74HCT244PW part is unused and in its original packaging.
Return procedure for SN74HCT244PW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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