Part A
74LCX125MTCX
Semi - conducteurs
- Lifecycle
- Active
- Stock
- 6950 PCS
- Package
- TSSOP-14
- Series
- Logique - Buffers, lecteurs, récepteurs, émetteurs - récepteurs
Replacement verdict
Not a drop-in replacement
The 74LCX125MTCX and 74LCX06MTCX are not functionally interchangeable despite sharing the same LCX logic family and TSSOP-14 package. The 74LCX125MTCX provides four independent non-inverting buffers with 3-state outputs, while the 74LCX06MTCX provides six inverting buffers with open-drain outputs. The differing channel count, output configuration, and drive characteristics require circuit-level redesign before substitution can be considered.
Different channel count
Different output type
Different logic function
External pull-up may be required
Parts at a glance
Part B
74LCX06MTCX
Fairchild Semiconductor Inc
- Lifecycle
- Active
- Stock
- 8775 PCS
- Series
- Logique - portes et Onduleurs
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74LCX125MTCX | 74LCX06MTCX | Why it matters |
|---|---|---|---|
| Logic Function | Quad Buffer with 3-State Outputs | Hex Inverter with Open-Drain Outputs | The core logic function determines whether the parts are functionally interchangeable; a buffer and an inverter perform fundamentally different signal operations. |
| Number of Channels | 4 | 6 | Channel count affects how many independent signal lines can be handled, impacting board layout and circuit design. |
| Output Type | 3-State | Open-Drain | Output type determines drive capability, bus sharing, and whether external pull-up resistors are required. |
| Output Drive Current | 24 mA | 24 mA | Drive current indicates the load the output can sink or source, affecting fan-out and signal integrity. |
| Propagation Delay | 6.5 ns | 5.5 ns | Propagation delay affects maximum operating frequency and timing margins in synchronous designs. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Supply voltage range must match the system rail to ensure proper logic levels and reliable operation. |
| Package Type | TSSOP-14 | TSSOP-14 | Package type affects footprint, thermal performance, and assembly compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range determines suitability for industrial or commercial environments. |
| Input Type | Standard CMOS | Standard CMOS | Input type influences input threshold levels and compatibility with upstream logic families. |
| Enable Control | Yes (Output Enable) | No | Enable control allows high-impedance state for bus sharing; its absence limits multiplexing and bus arbitration capability. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX125MTCX | 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, 24mA | -, 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 |
| Number of Elements | 4 | - |
| Number of Bits per Element | 1 | - |
| Output Type | 3-State | - |
Frequently asked questions
What are the primary functional differences between the 74LCX125MTCX and the 74LCX06MTCX?
The 74LCX125MTCX is a quad buffer/line driver with 3-state outputs, meaning its outputs can be placed in a high-impedance state for bus sharing. The 74LCX06MTCX is a hex inverter with open-drain outputs, which can only sink current and require an external pull-up resistor to achieve a logic HIGH.
Can the 74LCX125MTCX and 74LCX06MTCX be used interchangeably in a design?
No, they are not functionally interchangeable. The 74LCX125MTCX provides active drive for both HIGH and LOW logic levels with 3-state control, while the 74LCX06MTCX provides open-drain outputs that only pull LOW and invert the input signal. Substitution would require significant circuit redesign.
What are the package and pin count differences between the 74LCX125MTCX and 74LCX06MTCX?
Both devices are offered in a 14-pin TSSOP package (suffix MTC). However, their pinouts differ due to different functions: the 74LCX125MTCX has four buffers with separate output enable pins, while the 74LCX06MTCX has six inverters with no enable pins.
Which device is suitable for wired-OR or wired-AND bus configurations?
The 74LCX06MTCX, with its open-drain outputs, is suitable for wired-OR configurations when external pull-up resistors are used. The 74LCX125MTCX, having 3-state outputs, is intended for bus multiplexing but not for wired-logic configurations.
Do both the 74LCX125MTCX and 74LCX06MTCX operate at the same voltage range?
Yes, both are LCX-family devices and typically operate over a supply voltage range of 2.0 V to 3.6 V, with 5 V tolerant inputs, as specified in their respective manufacturer datasheets.
What is the difference in output drive current between the 74LCX125MTCX and 74LCX06MTCX?
The 74LCX125MTCX typically provides balanced drive of ±24 mA at 3.0 V VCC. The 74LCX06MTCX open-drain outputs typically sink 24 mA but do not source current; the HIGH level is provided by an external pull-up resistor.
Which device should be selected for level shifting from 3.3 V to 5 V?
The 74LCX06MTCX is often used for 3.3 V to 5 V level shifting because its open-drain output can be pulled up to 5 V, provided the pull-up resistor and bus capacitance meet timing requirements. The 74LCX125MTCX is not intended for direct 5 V output level shifting without additional circuitry.
Are the 74LCX125MTCX and 74LCX06MTCX available in the same tape and reel packaging?
Yes, both the 74LCX125MTCX and 74LCX06MTCX are commonly supplied in 14-pin TSSOP tape and reel packaging (suffix X), as indicated by their respective manufacturer ordering codes.