Part A
74LCX04MTCX
onsemi
- Lifecycle
- Active
- Stock
- 4842 PCS
- Package
- TSSOP-14
- Series
- Logic - Gates and Inverters
Replacement verdict
Not a drop-in replacement
The 74LCX04MTCX and 74LCXZ245MTC are not functionally interchangeable. The 74LCX04MTCX is a hex inverter, while the 74LCXZ245MTC is an octal bus transceiver with 3-state outputs. They differ in logic function, channel count, output type, and pin configuration, making direct substitution impossible without circuit redesign.
Different logic function
Different channel count
Different output type
Different pin configuration
Parts at a glance
Part B
74LCXZ245MTC
onsemi
- Lifecycle
- Active
- Stock
- 3529 PCS
- Package
- TSSOP-20
- Series
- Logic - 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 | 74LCXZ245MTC | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter | Octal Bus Transceiver | The two devices perform fundamentally different logic functions, so they are not functionally interchangeable in a circuit. |
| Number of Channels | 6 | 8 | Channel count determines how many independent signal lines the device can process. |
| Direction Control | Unidirectional | Bidirectional (with direction pin) | Bidirectional capability with a direction control pin allows the transceiver to route signals both ways, which an inverter cannot do. |
| Output Enable / Tri-State | No | Yes (OE active low) | Tri-state outputs allow the device to be disconnected from the bus, which is essential for shared bus architectures. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Both parts operate over the same low-voltage range, so they are compatible with the same 3.3 V logic systems. |
| Output Drive Current | ±24 mA | ±24 mA | Matching drive strength means both can drive similar loads without additional buffering. |
| Propagation Delay | 5.2 ns (max at 3.3 V) | 6.5 ns (max at 3.3 V) | Propagation delay affects timing margins in high-speed digital designs. |
| Package Type | TSSOP-14 | TSSOP-20 | Different pin counts and package sizes mean the parts are not drop-in footprint compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings ensure both parts suit the same industrial temperature environments. |
| Input Type | Schmitt-trigger capable (CMOS) | CMOS | Input characteristics affect noise immunity and compatibility with slow or noisy input signals. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX04MTCX | 74LCXZ245MTC |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74LCX | 74LCXZ |
| Part Status | Active | Obsolete |
| Logic Type | Inverter | Transceiver, Non-Inverting |
| Number of Elements | - | 1 |
| Number of Bits per Element | - | 8 |
| Output Type | - | 3-State |
| Current - Output High Low | 24mA, 24mA | 24mA, 24mA |
| Voltage - Supply | 2V ~ 3.6V | 2.7V ~ 3.6V |
| 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 basic functions of the 74LCX04MTCX and 74LCXZ245MTC?
The 74LCX04MTCX is a hex inverter with six independent NOT gates, while the 74LCXZ245MTC is an octal bus transceiver with 3-state outputs. They serve different logic functions and are not functionally interchangeable.
What logic family and operating voltage range do these devices support?
Both devices are part of the LCX low-voltage CMOS logic family and operate over a supply voltage range of 2.0 V to 3.6 V, with 3.3 V being the typical nominal supply.
Are the 74LCX04MTCX and 74LCXZ245MTC pin-compatible?
No. The 74LCX04MTCX is a 14-pin TSSOP device, while the 74LCXZ245MTC is a 20-pin TSSOP device. They have different pin counts, pinouts, and functions, so they cannot be used as drop-in replacements for each other.
What is the difference in output drive and bus interface capability?
The 74LCX04MTCX provides standard push-pull outputs for logic inversion. The 74LCXZ245MTC provides 3-state outputs with bus-hold capability, allowing it to drive and isolate bidirectional bus lines in bus-oriented systems.
Can the 74LCXZ245MTC be used to replace the 74LCX04MTCX in an existing design?
No. The 74LCXZ245MTC is an octal transceiver with direction and output-enable controls, while the 74LCX04MTCX is a hex inverter. Their logic functions, pinouts, and package sizes differ, so a direct replacement is not possible without redesigning the circuit.
What are the typical applications for each device?
The 74LCX04MTCX is typically used for signal inversion, clock or logic signal buffering, and waveform shaping. The 74LCXZ245MTC is typically used for bidirectional bus interfacing, data transfer between buses, and isolation of bus segments in 3.3 V systems.
Do both devices support 5 V tolerant inputs?
Yes. Both the 74LCX04MTCX and 74LCXZ245MTC are specified with 5 V tolerant inputs, allowing them to interface with 5 V logic signals when operating from a 3.3 V supply.
What package type do these devices use?
Both devices are offered in TSSOP packages. The 74LCX04MTCX uses a 14-pin TSSOP, and the 74LCXZ245MTC uses a 20-pin TSSOP.