Part A
74LCX04MTCX
온세미
- Lifecycle
- Active
- Stock
- 4842 PCS
- Package
- TSSOP-14
- Series
- 로직 - 도어 및 인버터
Replacement verdict
Not a drop-in replacement
The 74LCX04MTCX and 74LCXZ245MTCX are not functionally interchangeable. The 74LCX04MTCX is a hex inverter providing six independent NOT gates, while the 74LCXZ245MTCX is an octal bus transceiver with dual enable controls and direction pin. They differ in logic function, channel count, pinout, and I/O architecture, so substituting one for the other is not feasible without redesign.
Different logic function
Different channel count
Different pinout
Different I/O architecture
Parts at a glance
Part B
74LCXZ245MTCX
온세미
- Lifecycle
- Active
- Stock
- 9690 PCS
- Package
- TSSOP-20
- Series
- 논리 - 버퍼, 드라이브, 수신기, 트랜시버
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 | 74LCXZ245MTCX | 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 pins) | 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 | 2.3 V to 3.6 V | The minimum operating voltage differs, affecting compatibility in low-voltage systems. |
| Output Drive Current | ±24 mA | ±24 mA | Drive current determines the load the output can reliably drive; identical values indicate similar drive strength. |
| 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. |
| Input Tolerance | 5 V Tolerant Inputs | 5 V Tolerant Inputs/Outputs | 5 V tolerance allows interfacing with higher-voltage logic without damage, but the scope differs between the two parts. |
| Package | TSSOP-14 | TSSOP-20 | Different pin counts and package sizes affect PCB layout and footprint compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ranges indicate both parts are suitable for the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX04MTCX | 74LCXZ245MTCX |
|---|---|---|
| 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 primary functional differences between the 74LCX04MTCX and the 74LCXZ245MTCX?
The 74LCX04MTCX is a hex inverter, providing six independent NOT gates that invert logic signals. The 74LCXZ245MTCX is an octal bus transceiver with 3-state outputs, designed for bidirectional data transfer between two buses. They serve fundamentally different logic functions and are not functionally interchangeable.
Do the 74LCX04MTCX and 74LCXZ245MTCX share the same package and pinout?
Both devices are offered in the TSSOP-14 package (MTC suffix). However, their pinouts differ because the 74LCX04MTCX is a hex inverter with 14 pins (6 gates plus power/ground), while the 74LCXZ245MTCX is an octal transceiver with 20 pins in its standard configuration. The 74LCXZ245MTCX is not available in a 14-pin TSSOP; it typically uses a 20-pin TSSOP or similar. Therefore, they are not pin-to-pin compatible.
Can the 74LCX04MTCX be used as a direct drop-in replacement for the 74LCXZ245MTCX in an existing design?
No. The 74LCX04MTCX is a unidirectional hex inverter, while the 74LCXZ245MTCX is a bidirectional octal bus transceiver with 3-state outputs and direction control. They differ in logic function, pin count, pinout, and channel count. A direct substitution is not possible without redesigning the circuit.
What are the operating voltage and logic family specifications for both devices?
Both the 74LCX04MTCX and 74LCXZ245MTCX are part of the LCX family, which operates from a 2.0 V to 3.6 V supply voltage. They are designed for low-voltage, low-power applications and are compatible with 5 V tolerant inputs in some configurations, but always verify the specific datasheet for exact input/output voltage ratings.
Which device is better suited for bus-oriented applications?
The 74LCXZ245MTCX is specifically designed for bus-oriented applications. It provides octal bidirectional data transfer with 3-state outputs, allowing multiple devices to share a common bus. The 74LCX04MTCX is a general-purpose inverter and is not intended for bus interfacing.
Are the drive strengths and output current ratings the same for both components?
No. The 74LCX04MTCX typically provides ±24 mA output drive at 3.0 V, while the 74LCXZ245MTCX also offers ±24 mA drive at 3.0 V. However, the 74LCXZ245MTCX includes 3-state outputs and bus-hold or equivalent features depending on the specific variant. Always consult the manufacturer datasheet for exact drive current and derating information.
What are the typical propagation delays for these devices?
The 74LCX04MTCX has a typical propagation delay of approximately 4.5 ns at 3.3 V. The 74LCXZ245MTCX has a typical propagation delay of approximately 5.5 ns at 3.3 V. These values are for reference only and can vary with load, temperature, and supply voltage. Verify with the latest datasheet.
Do both devices support 5 V tolerant inputs?
The 74LCX04MTCX and 74LCXZ245MTCX are both specified with 5 V tolerant inputs, allowing them to interface with 5 V logic systems while operating at lower supply voltages. This is a common feature of the LCX family, but confirm the exact input voltage range in the respective datasheets.