Part A
74LCX244MTC
onsemi
- Lifecycle
- Active
- Stock
- 5042 PCS
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Not a drop-in replacement
The 74LCX244MTC and 74LCX00TTR are not functionally interchangeable. The 74LCX244MTC is an octal non-inverting buffer/line driver with 3-state outputs, while the 74LCX00TTR is a quad 2-input NAND gate. Their logic functions, channel counts, pinouts, and package types differ fundamentally, so neither device can directly substitute for the other in an existing design without significant circuit redesign.
Different logic function
Different channel count
Different pinout
Different package type
Parts at a glance
Part B
74LCX00TTR
STMicroelectronics
- Lifecycle
- Active
- Stock
- 6012 PCS
- Series
- Logic - Gates and Inverters
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 | 74LCX00TTR | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-State Outputs | Quad 2-Input NAND Gate | The logic function defines the fundamental operation of the device; these parts are not functionally interchangeable as they perform completely different logic operations. |
| Number of Circuits / Channels | 8 (2 groups of 4) | 4 gates | Channel count determines how many independent signal paths can be handled, affecting board layout and the number of components needed. |
| Output Type | 3-State (tri-state) | Push-Pull | 3-state outputs allow bus sharing by high-impedance disconnection, while push-pull outputs cannot be tied together without contention. |
| Number of Inputs per Element | 1 (per buffer) | 2 (per gate) | Input count per element determines the logic capability and how signals are combined within each functional block. |
| Package / Mounting Type | 20-TSSOP (0.173", 4.40mm Width), Surface Mount | 14-TSSOP (0.173", 4.40mm Width), Surface Mount | Package footprint and pin count must match the PCB layout; different packages are not drop-in compatible. |
| Number of Pins | 20 | 14 | Pin count affects PCB footprint and routing; mismatched pin counts prevent direct substitution. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Operating voltage range must be compatible with the system power rails for proper logic level translation and reliable operation. |
| Logic Family | LCX | LCX | The logic family determines input/output voltage thresholds, drive strength, and speed characteristics, ensuring compatibility with other logic devices. |
| Propagation Delay (max) | 6.5 ns at 3.3 V | 5.5 ns at 3.3 V | Propagation delay affects timing margins in synchronous systems; different delays may require timing re-analysis. |
| Output Drive Current (max) | ±24 mA | ±24 mA | Output drive current determines the ability to drive loads and other logic inputs; matching this ensures signal integrity is maintained. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX244MTC | 74LCX00TTR |
|---|---|---|
| Supplier | - | STMicroelectronics |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | NAND Gate |
| Number of Circuits | - | 4 |
| Number of Inputs | - | 2 |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Current - Quiescent (Max) | - | 10 µA |
| Current - Output High Low | - | 24mA, 24mA |
| Logic Level - Low | - | 0.8V |
| Logic Level - High | - | 2V |
| Max Propagation Delay @ V Max CL | - | 4.3ns @ 3.3V, 50pF |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | 74LCX244 | - |
| Number of Elements | 2 | - |
| Number of Bits per Element | 4 | - |
| Output Type | 3-State | - |
| Current - Output High, Low | 24mA, 24mA | - |
| Packaging | Tube | - |
Frequently asked questions
What are the primary functional differences between the 74LCX244MTC and the 74LCX00TTR?
The 74LCX244MTC is an octal buffer/line driver with 3-state outputs, designed for bus-oriented applications. The 74LCX00TTR is a quad 2-input NAND gate. They serve fundamentally different logic functions and are not functionally interchangeable.
Are the 74LCX244MTC and 74LCX00TTR pin-to-pin compatible?
No. The 74LCX244MTC is typically supplied in a 20-pin TSSOP package, while the 74LCX00TTR is supplied in a 14-pin TSSOP package. They have different pin counts and pinouts, so they cannot be used as direct drop-in replacements for each other.
Do both devices operate at the same supply voltage range?
Yes. Both the 74LCX244MTC and 74LCX00TTR are LCX-family devices and operate over a recommended supply voltage range of 2.0 V to 3.6 V, with 3.3 V being the nominal operating voltage.
What are the output drive capabilities of the 74LCX244MTC compared to the 74LCX00TTR?
The 74LCX244MTC provides balanced output drive of ±24 mA at 3.0 V, suitable for driving bus lines. The 74LCX00TTR provides ±24 mA output drive at 3.0 V as well, but its NAND gate outputs are intended for standard logic interfacing rather than bus driving.
Can the 74LCX244MTC be used to replace the 74LCX00TTR in a NAND gate circuit?
No. The 74LCX244MTC is a non-inverting buffer with 3-state outputs and does not perform the NAND logic function. Replacing a 74LCX00TTR with a 74LCX244MTC would not provide the required logic operation and would also require different PCB footprint and pinout.
What are the typical propagation delay specifications for these devices?
At 3.3 V, the 74LCX244MTC has a typical propagation delay of approximately 6.5 ns. The 74LCX00TTR has a typical propagation delay of approximately 5.5 ns at 3.3 V. Exact values should be verified from the respective manufacturer datasheets.
Are both devices available in the same package type?
No. The 74LCX244MTC is offered in a 20-pin TSSOP package, while the 74LCX00TTR is offered in a 14-pin TSSOP package. The package suffix "MTC" and "TTR" indicate different package and packing options from their respective manufacturers.
Do both devices feature 3-state outputs?
No. The 74LCX244MTC features 3-state outputs controlled by two active-low output enable pins. The 74LCX00TTR has standard push-pull outputs and does not provide a high-impedance state.