Part A
74LCX125MTCX
onsemi
- Lifecycle
- Active
- Stock
- 6950 PCS
- Package
- TSSOP-14
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Not a drop-in replacement
The 74LCX125MTCX and 74LCX02MTC are not functionally interchangeable. The 74LCX125MTCX is a quad non-inverting 3-state buffer with individual output enable control, while the 74LCX02MTC is a quad 2-input NOR gate with standard push-pull outputs. Their logic functions, output structures, and pin functions differ fundamentally, so neither device can directly substitute for the other in an existing design without circuit redesign.
Different logic function
Different output type
Different pin function
Different enable control
Parts at a glance
Part B
74LCX02MTC
onsemi
- Lifecycle
- Active
- Stock
- 6274 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 | 74LCX125MTCX | 74LCX02MTC | Why it matters |
|---|---|---|---|
| Logic Function | Quad Buffer with 3-State Outputs | Quad 2-Input NOR Gate | The logic function defines the fundamental operation of the device; a buffer and a NOR gate are not functionally interchangeable in a circuit. |
| Number of Gates/Channels | 4 | 4 | Both devices contain four independent elements, so the channel count is the same, but the type of element differs. |
| Output Type | 3-State | Push-Pull | 3-state outputs allow bus sharing and high-impedance isolation, while push-pull outputs are always actively driven; this affects bus interfacing capability. |
| Input Type | Standard CMOS | Standard CMOS | Both use standard CMOS inputs, so input threshold and loading characteristics are similar. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | The operating voltage range determines compatibility with 3.3 V and lower-voltage logic systems. |
| Propagation Delay (tpd) | 5.2 ns (max at 3.3 V) | 5.5 ns (max at 3.3 V) | Propagation delay affects timing margins and maximum operating frequency in synchronous designs. |
| Output Drive Current (IOH/IOL) | ±24 mA | ±24 mA | Drive current determines the ability to drive loads such as LEDs, transmission lines, or other logic inputs. |
| Package Type | TSSOP-14 | TSSOP-14 | Package type affects PCB footprint, thermal performance, and assembly compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range ensures reliable operation in industrial and commercial environments. |
| Pin Count | 14 | 14 | Pin count affects package size and PCB layout, though both share the same count here. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX125MTCX | 74LCX02MTC |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | NOR 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 | 24mA, 24mA |
| Logic Level - Low | - | 0.7V ~ 0.8V |
| Logic Level - High | - | 1.7V ~ 2V |
| Max Propagation Delay @ V Max CL | - | 5.2ns @ 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 74LCX02MTC?
The 74LCX125MTCX is a quad non-inverting buffer/line driver with 3-state outputs, while the 74LCX02MTC is a quad 2-input NOR gate. They perform fundamentally different logic functions and are not functionally interchangeable.
Do the 74LCX125MTCX and 74LCX02MTC share the same package and pinout?
Both devices are offered in a 14-lead TSSOP package (MTC suffix). However, their pinouts differ because the 74LCX125MTCX includes output enable pins and 3-state outputs, whereas the 74LCX02MTC has standard NOR gate inputs and outputs. PCB layouts are not directly compatible.
Are the 74LCX125MTCX and 74LCX02MTC compatible with 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.
Can the 74LCX125MTCX drive heavier loads than the 74LCX02MTC?
Both devices typically provide ±24 mA output drive at 3.0 V, as specified in the LCX family datasheets. The 74LCX125MTCX is optimized as a line driver with 3-state outputs, but the DC drive current ratings are comparable between the two devices.
What is the function of the 3-state outputs on the 74LCX125MTCX compared to the 74LCX02MTC?
The 74LCX125MTCX features 3-state outputs controlled by active-low output enable (OE) pins, allowing the outputs to be placed in a high-impedance state for bus sharing. The 74LCX02MTC does not have 3-state outputs; its outputs are always active and represent the NOR logic function of its inputs.
Are the 74LCX125MTCX and 74LCX02MTC interchangeable in a design?
No. They are not pin-to-pin or function-to-function replacements. The 74LCX125MTCX is a buffer/driver with enable control, while the 74LCX02MTC is a logic gate. Substitution would require a complete redesign of the surrounding circuit and PCB layout.
What are the operating temperature ranges for the 74LCX125MTCX and 74LCX02MTC?
Both devices are specified for the industrial temperature range of -40 °C to +85 °C, as stated in their respective manufacturer datasheets. This makes them suitable for a wide range of industrial and commercial applications.