Part A
74LCX125MTCX
온세미
- Lifecycle
- Active
- Stock
- 6950 PCS
- Package
- TSSOP-14
- Series
- 논리 - 버퍼, 드라이브, 수신기, 트랜시버
Replacement verdict
Not a drop-in replacement
The 74LCX125MTCX and 74LCX06MTC 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 74LCX06MTC provides six inverting buffers with open-drain outputs. The differing channel count, output configuration, and drive architecture require circuit-level redesign, and the open-drain outputs of the 74LCX06MTC mandate external pull-up resistors that are not required by the 3-state outputs of the 74LCX125MTCX.
Different output type
Different channel count
Different logic function
External pull-up may be required
Parts at a glance
Part B
74LCX06MTC
온세미
- Lifecycle
- Active
- Stock
- 7910 PCS
- Series
- 로직 - 도어 및 인버터
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 | 74LCX06MTC | Why it matters |
|---|---|---|---|
| Logic Function | Quad Buffer with 3-State Outputs | Hex Inverter with Open-Drain Outputs | The core logic function determines whether the devices 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 circuit design and board layout. |
| Output Type | 3-State (Tri-State) | Open-Drain | Output type determines drive capability, bus sharing, and whether external pull-up resistors are required. |
| Output Enable Control | Yes (per-channel OE pins) | No | Output enable allows high-impedance state for bus multiplexing; its absence limits direct substitution in shared-bus applications. |
| Signal Inversion | Non-Inverting | Inverting | Inversion changes the logic polarity, which is critical for correct signal behavior in a target circuit. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Matching supply voltage ranges ensures both devices operate within the same system power rails. |
| Logic Family | LCX | LCX | Same logic family implies compatible input thresholds, noise margins, and speed characteristics. |
| Package Type | TSSOP-14 | TSSOP-14 | Identical package and pin count allow the same PCB footprint, though pin functions may differ. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature ranges ensures both parts meet the same environmental requirements. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX125MTCX | 74LCX06MTC |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,onsemi |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| 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 74LCX06MTC?
The 74LCX125MTCX is a quad buffer/line driver with 3-state outputs, while the 74LCX06MTC is a hex inverter with open-drain outputs. The 74LCX125MTCX provides active drive in both HIGH and LOW states with a high-impedance state, whereas the 74LCX06MTC only pulls LOW and requires an external pull-up resistor for HIGH logic levels.
Are the 74LCX125MTCX and 74LCX06MTC pin-to-pin compatible?
No. The 74LCX125MTCX is a 14-pin TSSOP device with four buffers, each having an independent output enable pin. The 74LCX06MTC is also a 14-pin TSSOP device but contains six inverters with open-drain outputs. The pin functions and signal assignments differ, so they are not direct drop-in replacements.
Can the 74LCX125MTCX and 74LCX06MTC operate at the same supply voltage range?
Yes. Both devices are part of the LCX family and operate over a supply voltage range of 2.0 V to 3.6 V, with typical operation at 3.3 V. They also feature 5 V tolerant inputs and outputs, allowing interfacing with 5 V logic systems.
What is the difference in output drive capability between the 74LCX125MTCX and the 74LCX06MTC?
The 74LCX125MTCX provides standard balanced drive with ±24 mA output current at 3.0 V VCC. The 74LCX06MTC has open-drain outputs with a specified sink current of 24 mA at 3.0 V VCC, but it cannot source current; the HIGH level is achieved only through an external pull-up resistor.
Which device is better suited for wired-OR or wired-AND logic applications?
The 74LCX06MTC is better suited for wired-OR logic because its open-drain outputs can be tied together with a single pull-up resistor to implement a wired-OR function. The 74LCX125MTCX has 3-state outputs and cannot be directly wired together without external logic to avoid bus contention.
Do both the 74LCX125MTCX and 74LCX06MTC support live insertion or hot-swap applications?
Yes. Both devices feature power-down high-impedance outputs and are designed to support live insertion and hot-swap applications. The 74LCX125MTCX achieves this through its 3-state outputs, while the 74LCX06MTC has open-drain outputs that remain high-impedance when VCC is 0 V.
What are the package and pin count specifications for the 74LCX125MTCX and 74LCX06MTC?
Both devices are offered in a 14-pin TSSOP package, designated by the MTC suffix. The 74LCX125MTCX uses the TSSOP-14 package, and the 74LCX06MTC also uses the TSSOP-14 package. They share the same package dimensions and lead pitch but have different internal die configurations.
Can the 74LCX125MTCX be used to replace the 74LCX06MTC in an existing design without modification?
No. The 74LCX125MTCX cannot directly replace the 74LCX06MTC because the pin functions, output types, and logic functions differ. The 74LCX06MTC requires external pull-up resistors and has six inverters, while the 74LCX125MTCX has four buffers with 3-state outputs and no pull-up requirement. A redesign of the PCB and logic is necessary.