Part A
74LCX244MTC
onsemi
- Lifecycle
- Active
- Stock
- 5042 PCS
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Compatible functional replacement candidate
The 74LCX244MTC and 74LCX244TTR are functionally equivalent octal buffers/line drivers from the same 74LCX logic family, sharing identical logic function, channel count, supply voltage range, and drive characteristics. Both are viable drop-in replacements for one another in terms of electrical performance, with the primary distinction being package mounting type and packing format. Designers should verify board-level footprint compatibility before substituting, as one device is a surface-mount SOIC package while the other is a TSSOP package supplied on tape and reel.
Logic Function
High match
Channel Count
High match
Supply Voltage Range
High match
Package Type
Validation required
Parts at a glance
Part B
74LCX244TTR
STMicroelectronics
- Lifecycle
- Active
- Stock
- 7876 PCS
- Package
- TSSOP-20
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74LCX244MTC | 74LCX244TTR | Why it matters |
|---|---|---|---|
| Manufacturer | onsemi (Fairchild) | STMicroelectronics | Different manufacturers may have subtle differences in process, quality documentation, and second-source qualification requirements. |
| Logic Family | LCX (Low-Voltage CMOS) | LCX (Low-Voltage CMOS) | Same logic family ensures compatible input/output thresholds and switching behavior for direct substitution. |
| Function | Octal Buffer/Line Driver, 3-State | Octal Buffer/Line Driver, 3-State | Identical logic function is essential for functional substitutability in a given circuit. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Matching operating voltage range ensures the device works in the same power rail conditions. |
| Number of Channels | 8 | 8 | Same channel count preserves the I/O capacity of the original design. |
| Output Type | 3-State | 3-State | 3-state outputs allow bus sharing; identical output type maintains bus arbitration behavior. |
| Package / Case | 20-TSSOP | 20-TSSOP | Same package footprint allows drop-in PCB replacement without layout changes. |
| Mounting Type | Surface Mount | Surface Mount | Matching mounting type is required for compatibility with the existing assembly process. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature range ensures both parts meet the same environmental requirements. |
| Packaging / Ordering | Tube | Tape & Reel | Different packaging affects handling, automated assembly, and minimum order quantities. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX244MTC | 74LCX244TTR |
|---|---|---|
| Supplier | - | STMicroelectronics |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 2 | 2 |
| Number of Bits per Element | 4 | 4 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | - | 24mA, 24mA |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C (TA) | -55°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | 74LCX244 | - |
| Current - Output High, Low | 24mA, 24mA | - |
| Packaging | Tube | - |
Frequently asked questions
Are the 74LCX244MTC and 74LCX244TTR functionally equivalent?
Yes. Both are octal buffers/line drivers with 3-state outputs from the 74LCX244 family, featuring non-inverting outputs and the same logic function. The 74LCX244MTC is the Fairchild/ON Semiconductor part number in a 20-lead TSSOP package, while the 74LCX244TTR is the STMicroelectronics part number in a 20-lead TSSOP package. Both provide the same logic function and pinout.
What are the key differences between the 74LCX244MTC and 74LCX244TTR?
The primary differences are the manufacturer and the part numbering system. The 74LCX244MTC is manufactured by ON Semiconductor (formerly Fairchild), while the 74LCX244TTR is manufactured by STMicroelectronics. Both are offered in the same 20-lead TSSOP package with identical pin assignments. Electrical specifications such as supply voltage range (2.0 V to 3.6 V), output drive, and propagation delay are comparable between the two devices.
Can the 74LCX244MTC and 74LCX244TTR be used interchangeably in a design?
In most cases, yes, provided the electrical and timing specifications are verified against the target design requirements. Both devices share the same pinout, package footprint (20-lead TSSOP), and logic function. However, designers should confirm that parameters such as propagation delay, output drive current, and input/output voltage thresholds meet the specific application requirements, as minor differences may exist between manufacturers.
What is the operating voltage range for the 74LCX244MTC and 74LCX244TTR?
Both devices operate over a supply voltage range of 2.0 V to 3.6 V, making them suitable for low-voltage 3.3 V and mixed-voltage applications. They are designed for 3.3 V systems with 5 V tolerant inputs, allowing interfacing with 5 V logic without damage.
What package type do the 74LCX244MTC and 74LCX244TTR use?
Both the 74LCX244MTC and 74LCX244TTR are supplied in the 20-lead TSSOP (Thin Shrink Small Outline Package). The "MTC" suffix in the ON Semiconductor part number and the "TTR" suffix in the STMicroelectronics part number both denote the TSSOP package option. The package dimensions and PCB land patterns are compatible.
Do the 74LCX244MTC and 74LCX244TTR have 5 V tolerant inputs?
Yes. Both devices feature 5 V tolerant inputs and outputs when operating at VCC = 3.0 V to 3.6 V, allowing them to interface with 5 V logic levels in mixed-voltage systems. This is a standard characteristic of the LCX family. Designers should verify the specific datasheet for the exact input/output voltage tolerance conditions.
What is the output drive capability of the 74LCX244MTC and 74LCX244TTR?
Both devices typically provide ±24 mA output drive at VCC = 3.0 V, which is suitable for driving bus lines and moderate capacitive loads. The 3-state outputs allow the device to be connected directly to a bus-organized system without the need for external interface components. Actual drive current should be confirmed from the respective manufacturer datasheets.
Are the 74LCX244MTC and 74LCX244TTR RoHS compliant?
Both the ON Semiconductor 74LCX244MTC and the STMicroelectronics 74LCX244TTR are available in RoHS-compliant versions. However, compliance status can vary by production lot and ordering option. Designers should verify the specific ordering part number and manufacturer declaration to confirm RoHS and REACH compliance for their application.