Part A
74LCX04MTCX
onsemi
- Lifecycle
- Active
- Stock
- 4842 PCS
- Package
- TSSOP-14
- Series
- Lógica - Gates e Inverters
Replacement verdict
Not a drop-in replacement
The 74LCX04MTCX and 74LCX07MTC are not functionally interchangeable despite sharing the same TSSOP-14 footprint and LCX-family low-voltage CMOS process. The 74LCX04MTCX provides standard CMOS push-pull outputs with active pull-up and pull-down drive, whereas the 74LCX07MTC features open-drain outputs that require external pull-up resistors and cannot source current. This fundamental output-stage difference alters logic-level behavior, drive capability, and system-level design requirements, so the two devices cannot be substituted without circuit modification and validation.
Different output type
External pull-up may be required
Different drive capability
Different logic behavior
Parts at a glance
Part B
74LCX07MTC
onsemi
- Lifecycle
- Active
- Stock
- 5497 PCS
- Package
- TSSOP-14
- Series
- Lógica - Buffers, Drivers, Receivers, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74LCX04MTCX | 74LCX07MTC | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter | Hex Buffer with Open-Drain Outputs | Determines the fundamental signal operation; an inverter provides complementary output while an open-drain buffer requires an external pull-up and cannot source current. |
| Output Type | Push-Pull (Totem-Pole) | Open-Drain | Push-pull outputs actively drive both high and low, whereas open-drain outputs only sink current and need a pull-up resistor, affecting drive strength and wired-OR capability. |
| Number of Circuits | 6 | 6 | Both devices contain six independent gates, so channel count is identical and does not affect substitutability. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Both operate over the same low-voltage range, allowing use in 2.5 V and 3.3 V systems without level shifting. |
| Output Drive Current (IOL) | 24 mA | 24 mA | Identical sink current capability means both can drive similar loads when pulling low, but the open-drain device cannot source current. |
| Propagation Delay (tPD) | 5.2 ns (max at 3.3 V) | 5.5 ns (max at 3.3 V) | Slight timing difference may affect high-speed signal integrity and timing margins in synchronous designs. |
| Input Type | Standard CMOS | Standard CMOS | Both accept standard CMOS input levels, so input compatibility is the same for interfacing with other logic. |
| Package | TSSOP-14 | TSSOP-14 | Same package and pin count allow direct PCB footprint compatibility, but pin functions differ due to output type. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Identical temperature ratings ensure both can be used in the same industrial and commercial environments. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX04MTCX | 74LCX07MTC |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,onsemi |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Inverter | Buffer, Non-Inverting |
| Number of Elements | - | 6 |
| Number of Bits per Element | - | 1 |
| Output Type | - | Open Drain |
| Current - Output High Low | 24mA, 24mA | -, 32mA |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Circuits | 6 | - |
| Number of Inputs | 1 | - |
| Current - Quiescent (Max) | 10 µA | - |
| Logic Level - Low | 0.7V ~ 0.8V | - |
| Logic Level - High | 1.7V ~ 2V | - |
| Max Propagation Delay @ V Max CL | 5.2ns @ 3.3V, 50pF | - |
Frequently asked questions
What are the main functional differences between the 74LCX04MTCX and the 74LCX07MTC?
The 74LCX04MTCX contains six independent inverters with standard push-pull CMOS outputs. The 74LCX07MTC contains six independent non-inverting buffers with open-drain outputs. The 74LCX04MTCX actively drives both HIGH and LOW logic levels, while the 74LCX07MTC can only pull LOW and requires an external pull-up resistor to establish a HIGH level.
Are the 74LCX04MTCX and 74LCX07MTC pin-to-pin compatible?
Yes. Both devices are offered in the same 14-lead TSSOP package with the same pinout: pins 1 through 6 are the inputs, pins 7 and 14 are GND and VCC respectively, and pins 8 through 13 are the outputs. This shared pinout allows the two devices to be interchanged on an existing PCB footprint, provided the output-stage differences are accounted for in the design.
Can the 74LCX07MTC be used as a direct drop-in replacement for the 74LCX04MTCX?
Not without design changes. The 74LCX04MTCX provides active pull-up and pull-down outputs, whereas the 74LCX07MTC has open-drain outputs that cannot source current. Replacing the 74LCX04MTCX with the 74LCX07MTC requires adding external pull-up resistors on every output that must reach a logic HIGH level, and the resulting rise time and power consumption must be re-evaluated.
What are the recommended operating conditions for the 74LCX04MTCX and 74LCX07MTC?
Both devices are specified for a supply voltage (VCC) range of 2.0 V to 3.6 V, with 2.5 V and 3.3 V as the primary nominal operating voltages. They are characterized for operation over the -40 °C to +85 °C industrial temperature range. These parameters are common to the LCX family and are documented in the respective manufacturer datasheets.
What is the difference in output drive current between the 74LCX04MTCX and the 74LCX07MTC?
The 74LCX04MTCX is specified with ±24 mA output drive at VCC = 3.0 V, allowing it to source and sink current. The 74LCX07MTC is specified with 24 mA output sink current at VCC = 3.0 V but has no source current capability because of its open-drain output structure. The sink current ratings are comparable, but only the 74LCX04MTCX can drive a logic HIGH output.
Which device is better suited for wired-OR or bus applications?
The 74LCX07MTC is better suited for wired-OR and bus applications because its open-drain outputs can be tied together with a single pull-up resistor to implement a wired-OR function. The 74LCX04MTCX has push-pull outputs and must not have its outputs tied together, as this can cause contention and excessive current flow.
Do the 74LCX04MTCX and 74LCX07MTC support 5 V tolerant inputs?
Yes. Both devices feature 5 V tolerant inputs, allowing them to accept input voltages up to 5.5 V while operating from a 2.0 V to 3.6 V supply. This makes both parts suitable for level translation from 5 V logic to 3.3 V logic without additional circuitry. The 5 V tolerance applies to the inputs only and does not extend to the supply pin or, in the case of the 74LCX07MTC, to the open-drain output when pulled above VCC.
What is the propagation delay specification for the 74LCX04MTCX and the 74LCX07MTC?
Both devices are specified with a maximum propagation delay of 5.5 ns at VCC = 3.0 V and 6.5 ns at VCC = 2.5 V, measured with a 50 pF load. The 74LCX07MTC propagation delay is specified with a 500 Ω pull-up resistor to VCC, reflecting its open-drain output configuration. These timing values are documented in the respective manufacturer datasheets.