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onsemi 74ACT244MTC
- Part No.:
- 74ACT244MTC
- Manufacturer:
- onsemi
- Package:
- 20-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
74ACT244MTC.pdf
- Description:
- IC BUFF NON-INVERT 5.5V 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,635
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Product details
Overview
74ACT244MTC from ON Semiconductor is an octal non-inverting 3-STATE buffer/line driver designed for memory address and bus driving in digital systems. It features TTL-compatible inputs, ±24mA output drive capability, 5V supply operation (4.5–5.5V), and propagation delays as low as 6.5ns at VCC = 5V. It is commonly used in microprocessor address/data bus interfacing and peripheral expansion.
For engineers reviewing the 74ACT244MTC datasheet, pinout, applications, or equivalent options, key selection considerations include its 3-STATE dual-enable architecture, TSSOP-20 package footprint, 5V logic compatibility, and guaranteed AC/ACT family timing performance across −40°C to +85°C.
Technical Context
The 74ACT244MTC implements two independent 4-bit groups (I0–I3/O0–O3 and I4–I7/O4–O7), each controlled by a dedicated 3-STATE enable input (OE1 on pins 12,14,16,18; OE2 on pins 3,5,7,9). Its TTL-compatible inputs accept standard 5V logic thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V), enabling direct interface with legacy microcontrollers and peripherals.
Each output delivers ±24mA sink/source current under load while maintaining VOL ≤ 0.5V and VOH ≥ 3.7V at VCC = 4.5V, supporting robust bus termination and fanout. The device operates exclusively within 4.5–5.5V supply range and is not rated for 3.3V-only or mixed-voltage operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5V to 5.5V - Requires stable 5V rail; not functional below 4.5V or above 5.5V. |
| Output Drive | ±24mA - Supports direct connection to 50Ω transmission lines or multiple TTL loads without external buffers. |
| Propagation Delay | 6.5ns typical (tPLH/tPHL @ VCC=5V, CL=50pF) - Enables reliable operation in 100+ MHz bus systems with margin. |
| 3-STATE Enable Time | 6.0ns typical (tPZH @ VCC=5V) - Minimizes bus contention during direction switching in bidirectional data paths. |
| Input Thresholds | VIH ≥ 2.0V, VIL ≤ 0.8V - Fully compatible with standard TTL logic families and 5V microcontroller GPIO outputs. |
| Operating Temperature | −40°C to +85°C - Qualified for industrial-grade embedded control and computing applications. |
| Package | TSSOP-20 (JEDEC MO-153, 4.4mm wide) - Surface-mount footprint with 0.65mm pitch; optimized for high-density PCB layouts. |
Pinout & Package
74ACT244MTC uses a 20-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 4.4mm body width, 0.65mm lead pitch, and exposed pad not present. Pin numbering follows standard DIP/SOIC convention with pin 1 marked by a dot or bevel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19, 20 | VCC, GND (x2) | Single 5V supply rail and dual ground connections - Decoupling required at both ends of the package for noise immunity. |
| 2–9, 11–18 | I0–I3, I4–I7 / O0–O3, O4–O7 | Two independent 4-bit input/output channels - Inputs are TTL-compatible; outputs are 3-STATE with separate enables. |
| 12, 14, 16, 18 | OE1 (active-low) | Enables outputs O0–O3 when low - Grouped on even pins for synchronous control of first quad. |
| 3, 5, 7, 9 | OE2 (active-low) | Enables outputs O4–O7 when low - Grouped on odd pins for independent control of second quad. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-compatible inputs | Accepts standard 5V TTL voltage levels (VIH ≥ 2.0V, VIL ≤ 0.8V), eliminating level-shifting requirements in mixed-logic systems. |
| High-output drive strength | ±24mA per output ensures reliable signal integrity across unterminated or lightly loaded buses up to 15cm trace length. |
| Dual independent 3-STATE enables | OE1 and OE2 allow selective activation of two 4-bit groups - critical for time-multiplexed address/data bus partitioning. |
| Low quiescent ICC | Max 40µA at TA = −40°C to +85°C - Reduces static power in always-on system management functions. |
| Industrial temperature range | Rated for −40°C to +85°C operation - Validated for use in programmable logic controllers, motor drives, and factory automation hardware. |
Applications
| Memory Address Buffering | Microcontroller Bus Expansion |
|---|---|
|
Use Scenario: Driving 16-bit address bus from an 8-bit microcontroller using time-multiplexed lower/upper byte addressing. IC Role / Device Role / Timing Role: Acts as octal latchless address driver with group-selectable 3-STATE control to isolate upper/lower address segments during multiplexing cycles. Use Value: Eliminates need for additional latches or glue logic; enables direct interface between 8-bit MCU and 16-bit memory subsystems. |
Use Scenario: Expanding GPIO count of an ARM Cortex-M0+ MCU to drive parallel LCD controller and SD card interface simultaneously. IC Role / Device Role / Timing Role: Provides bidirectional 3-STATE buffering between MCU data bus and peripheral data lines, with OE1/OE2 synchronized to peripheral chip selects. Use Value: Prevents bus contention during peripheral arbitration; supports concurrent access to display and storage without software delay penalties. |
| Industrial I/O Module Interface | Legacy ISA Bus Signal Conditioning |
|
Use Scenario: Isolating field-side digital inputs (24V sensors) and driving relay outputs in a DIN-rail PLC I/O module. IC Role / Device Role / Timing Role: Buffers conditioned logic-level signals between isolation barriers and FPGA-based control logic; OE pins tied to FPGA configuration state. Use Value: Provides noise-immune signal translation with fast edge rates (≥125mV/ns min) suitable for noisy factory environments. |
Use Scenario: Replacing obsolete 74LS244 in retro-computing restoration projects requiring ISA bus add-in card compatibility. IC Role / Device Role / Timing Role: Serves as drop-in logic-level translator for ISA address/data strobes, leveraging identical pinout and 3-STATE behavior. Use Value: Delivers superior speed (6.5ns vs. 15ns LS) and drive strength (24mA vs. 8mA) while maintaining full mechanical and electrical backward compatibility. |
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 |
|---|---|---|---|
| SN74ACT244N | PDIP-20 package; same AC/ACT electrical specs and pinout. | Through-hole mounting only; unsuitable for high-density SMT designs. | Select when manual prototyping, legacy board rework, or socket-based test fixtures are required. |
| 74LCX244MTCX | Lower VCC range (2.0–3.6V); CMOS inputs; 24mA drive at 3.3V. | Designed for 3.3V systems; not TTL-compatible; incompatible with 5V logic thresholds. | Select only for pure 3.3V domains; requires level-shifting if interfacing with 5V peripherals. |
Compared with SN74ACT244N and 74LCX244MTCX, the 74ACT244MTC uniquely combines 5V TTL compatibility, surface-mount TSSOP-20 packaging, and industrial temperature rating-making it optimal for new 5V embedded designs where density, reliability, and legacy interface support are jointly required.
Availability
74ACT244MTC is available at Aetrix Electronics and suitable for industrial control systems, microcontroller bus expansion, and legacy interface adaptation requiring stable component supply and long-term manufacturability.
Supply support for 74ACT244MTC 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
ON Semiconductor (formerly Fairchild Semiconductor) is a global semiconductor manufacturer specializing in power management, analog, logic, and discrete devices for automotive, industrial, and cloud infrastructure markets.
The 74ACT244MTC belongs to ON Semiconductor's legacy AC/ACT logic family, engineered for high-speed, low-power 5V digital interfacing in industrial and computing applications where reliability and pin compatibility with industry-standard 74-series logic are essential.
FAQ
What is the recommended operating voltage range for the 74ACT244MTC?
The 74ACT244MTC is specified for operation only between 4.5V and 5.5V. Operation outside this range is not guaranteed and may result in incorrect logic states or increased ICC. Unlike AC-series variants, the ACT version does not support 3.3V or 2.5V supply rails - its TTL-compatible inputs require minimum 2.0V VIH, which is only assured within the 4.5–5.5V window.
Does the 74ACT244MTC support true bidirectional data flow?
No, the 74ACT244MTC is a unidirectional octal buffer: inputs (I0–I7) drive corresponding outputs (O0–O7) only. It lacks internal direction control or bus transceiver functionality. For bidirectional applications, external control logic must manage OE1/OE2 sequencing and ensure no simultaneous driving of the same bus line from multiple sources.
Can the 74ACT244MTC be used as a direct replacement for 74LS244 in existing designs?
Yes, the 74ACT244MTC is pin-compatible and functionally equivalent to 74LS244 in TSSOP-20 form, with identical pinout and 3-STATE behavior. However, it offers faster propagation (6.5ns vs. 15ns), higher output drive (±24mA vs. ±8mA), and lower ICC - all while maintaining TTL-compatible input thresholds. No PCB changes are required for drop-in replacement.
What is the maximum capacitive load the 74ACT244MTC can drive reliably?
The 74ACT244MTC is characterized for CL = 50pF in AC timing specifications, and its output drive strength (±24mA) supports stable signal edges into typical PCB trace capacitance plus up to ~3–4 standard TTL inputs (≈15–20pF total). For loads exceeding 75pF, propagation delay increases and edge rate degrades - verify timing margins in final layout using IBIS models or oscilloscope validation.
Is the 74ACT244MTC RoHS compliant and lead-free?
Yes, the 74ACT244MTC is lead-free and complies with JEDEC J-STD-020B reflow standards. All packages, including the MTC20 TSSOP variant, are manufactured to RoHS Directive 2011/65/EU requirements and carry appropriate marking per ON Semiconductor's compliance documentation.
74ACT244MTC Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74ACT
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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:
- 24mA, 24mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP
74ACT244MTC FAQ
1.How can I place an order for 74ACT244MTC through Aetrix?
Please submit a Request for Quotation (RFQ) for 74ACT244MTC 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 74ACT244MTC reliable?
The price and inventory of 74ACT244MTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74ACT244MTC is usually 5 days.
3.What payment methods are accepted for 74ACT244MTC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74ACT244MTC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74ACT244MTC?
74ACT244MTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74ACT244MTC 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 74ACT244MTC?
For technical support, including 74ACT244MTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74ACT244MTC requirements.
6.How does Aetrix verify that 74ACT244MTC is sourced from the original manufacturer or authorized distributors?
All 74ACT244MTC 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 74ACT244MTC meets industry standards.
7.What is the process for return or replacement of 74ACT244MTC?
All 74ACT244MTC units undergo pre-shipment inspection (PSI). If there is an issue with 74ACT244MTC, 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 74ACT244MTC part is unused and in its original packaging.
Return procedure for 74ACT244MTC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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