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 74LCX06MTCX are not functionally interchangeable. The 74LCX244MTC is a non-inverting octal buffer/line driver with 3-state outputs, while the 74LCX06MTCX is a hex inverter with open-drain outputs. They differ in logic function, channel count, output configuration, and drive characteristics, so substituting one for the other requires circuit redesign and cannot be treated as a direct replacement.
Different logic function
Different channel count
Different output type
External pull-up may be required
Parts at a glance
Part B
74LCX06MTCX
Fairchild Semiconductor
- Lifecycle
- Active
- Stock
- 8775 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 | 74LCX06MTCX | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-State Outputs | Hex Inverter with Open-Drain Outputs | The core logic function determines whether the devices are functionally interchangeable; a buffer/driver and an inverter perform fundamentally different signal operations. |
| Number of Channels | 8 | 6 | Channel count affects how many independent signal lines can be handled, impacting circuit design and board layout. |
| Output Type | 3-State | Open-Drain | Output type dictates how the device interfaces with a bus or load; 3-state allows high-impedance disconnection, while open-drain requires external pull-up resistors. |
| Input Type | Non-Inverting | Inverting | Signal polarity through the device must match the intended logic; substituting one for the other would invert the signal and break functionality. |
| Propagation Delay (tpd) | 6.5 ns (max at 3.3V) | 5.5 ns (max at 3.3V) | Propagation delay affects timing margins in synchronous systems; a slower device may violate setup/hold requirements. |
| Output Drive Current (IOL/IOH) | ±24 mA | 24 mA (sink only) | Drive current determines the ability to drive loads; open-drain outputs can only sink current, requiring pull-ups for logic high. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Both devices operate over the same low-voltage range, ensuring compatibility with 3.3V and lower-voltage logic systems. |
| Package Type | TSSOP-20 | TSSOP-14 | Package footprint and pin count must match the PCB layout; different packages are not drop-in replacements. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Both devices support industrial temperature ranges, making them suitable for similar environmental conditions. |
| Pin Count | 20 | 14 | Pin count directly affects PCB footprint and routing; devices with different pin counts cannot be interchanged without board redesign. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX244MTC | 74LCX06MTCX |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74LCX | 74LCX |
| Part Status | Active | Active |
| Logic Type | Buffer, Non-Inverting | Inverter |
| Number of Circuits | - | 6 |
| Number of Inputs | - | 1 |
| Features | - | Open Drain |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Current - Quiescent (Max) | - | 10 µA |
| Current - Output High Low | - | -, 24mA |
| Logic Level - Low | - | 0.7V ~ 0.8V |
| Logic Level - High | - | 1.7V ~ 2V |
| Max Propagation Delay @ V Max CL | - | 3.7ns @ 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 74LCX06MTCX?
The 74LCX244MTC is an octal buffer/line driver with 3-state outputs, designed for non-inverting signal buffering and bus driving. The 74LCX06MTCX is a hex inverter with open-drain outputs, intended for inverting logic and wired-OR/wired-AND applications. They differ in logic function, channel count, and output type.
Are the 74LCX244MTC and 74LCX06MTCX pin-to-pin compatible?
No. The 74LCX244MTC is a 20-pin TSSOP device with 3-state outputs and an output-enable structure, while the 74LCX06MTCX is a 14-pin TSSOP device with open-drain outputs. Their pin counts, pinouts, and package sizes differ, so they are not drop-in replacements.
Can the 74LCX244MTC and 74LCX06MTCX operate from the same supply voltage range?
Yes. Both devices are part of the LCX family and are specified for a 2.0 V to 3.6 V VCC operating range, making them compatible with low-voltage 2.5 V and 3.3 V logic systems.
What is the difference in output drive capability between the 74LCX244MTC and the 74LCX06MTCX?
The 74LCX244MTC provides standard push-pull 3-state outputs with specified DC output drive currents, typically ±24 mA at 3.0 V VCC. The 74LCX06MTCX has open-drain outputs, which sink current but do not source current, and its output high state is high-impedance, requiring an external pull-up resistor.
Which device is better suited for driving a shared bus or wired-OR configuration?
The 74LCX06MTCX is better suited for wired-OR or wired-AND configurations because its open-drain outputs allow multiple outputs to be tied together with a single pull-up resistor. The 74LCX244MTC has 3-state outputs intended for bus driving but not for direct wired-OR connection without additional logic.
Do both the 74LCX244MTC and 74LCX06MTCX support 5 V tolerant inputs?
Yes. Both devices feature 5 V tolerant inputs and outputs (when VCC is within the specified operating range), allowing them to interface with 5 V logic systems without additional level shifting in many applications.
What are the typical propagation delay characteristics of the 74LCX244MTC and 74LCX06MTCX?
Both devices are fabricated with advanced CMOS technology and offer similar high-speed performance. The 74LCX244MTC typically has a propagation delay of approximately 6.5 ns at 3.3 V VCC, while the 74LCX06MTCX typically has a propagation delay of approximately 5.5 ns at 3.3 V VCC, depending on load conditions and manufacturer specifications.
Are the 74LCX244MTC and 74LCX06MTCX available in the same package type?
Both devices are offered in TSSOP packages, but with different pin counts. The 74LCX244MTC is a 20-pin TSSOP, and the 74LCX06MTCX is a 14-pin TSSOP. The package body widths are similar, but the footprint and pin count differ.