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 74LCX06MTC are not functionally interchangeable despite sharing the same 14-pin TSSOP footprint and LCX-family low-voltage CMOS process. The 74LCX04MTCX provides standard buffered CMOS inverter outputs, whereas the 74LCX06MTC employs open-drain outputs that require external pull-up resistors and offer no active high drive. Because output structure, drive behavior, and system-level interfacing differ fundamentally, the 74LCX06MTC cannot directly replace the 74LCX04MTCX in an existing design without circuit modification and revalidation.
Different output type
External pull-up may be required
Different drive capability
Different logic function
Parts at a glance
Part B
74LCX06MTC
onsemi
- Lifecycle
- Active
- Stock
- 7910 PCS
- Series
- Lógica - Gates e 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 | 74LCX04MTCX | 74LCX06MTC | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter | Hex Inverter with Open-Drain Outputs | Determines the output drive type; open-drain outputs require an external pull-up resistor and cannot source current, affecting direct substitutability. |
| Output Type | Push-Pull (Totem-Pole) | Open-Drain | Push-pull outputs actively drive both high and low, while open-drain outputs only pull low, requiring external circuitry for logic high. |
| Output Drive Current (IOL) | 24 mA | 24 mA | Both can sink 24 mA, but the 74LCX06MTC cannot source current, so the drive capability differs in practice. |
| Output Drive Current (IOH) | -24 mA | 0 mA (open-drain, no source current) | The 74LCX04MTCX can source current to drive a logic high, while the 74LCX06MTC cannot, requiring a pull-up resistor. |
| Propagation Delay (tPD) | 5.2 ns (max at 3.3V) | 5.2 ns (max at 3.3V) | Similar delay, but open-drain output rise time depends on external pull-up, affecting overall timing in a circuit. |
| 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, but the output configuration difference affects system-level compatibility. |
| Input Type | Standard CMOS | Standard CMOS | Identical input characteristics, but the output stage difference means they are not direct substitutes in all applications. |
| Package | TSSOP-14 | TSSOP-14 | Same package and pinout, allowing physical drop-in replacement, but electrical differences remain. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Identical temperature range, so environmental suitability is the same for both parts. |
| Number of Circuits | 6 | 6 | Both provide six inverter circuits, but the output type difference is the key functional distinction. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX04MTCX | 74LCX06MTC |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,onsemi |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Inverter | Inverter |
| Number of Circuits | 6 | 6 |
| Number of Inputs | 1 | 1 |
| Features | - | Open Drain |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Current - Quiescent (Max) | 10 µA | 10 µA |
| Current - Output High Low | 24mA, 24mA | -, 24mA |
| Logic Level - Low | 0.7V ~ 0.8V | 0.7V ~ 0.8V |
| Logic Level - High | 1.7V ~ 2V | 1.7V ~ 2V |
| Max Propagation Delay @ V Max CL | 5.2ns @ 3.3V, 50pF | 3.7ns @ 3.3V, 50pF |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the main functional differences between the 74LCX04MTCX and the 74LCX06MTC?
The 74LCX04MTCX contains six independent inverters with standard push-pull CMOS outputs. The 74LCX06MTC contains six independent inverters with open-drain outputs, which require external pull-up resistors to define the high logic level.
Are the 74LCX04MTCX and 74LCX06MTC pin-to-pin compatible?
Yes. Both devices are offered in the same 14-pin TSSOP package (MTC suffix) and share the same pinout: pins 1 through 6 are inputs, pins 7 and 14 are ground and VCC respectively, and pins 8 through 13 are outputs. This allows the 74LCX06MTC to be used in place of the 74LCX04MTCX on an existing PCB when open-drain behavior is required or acceptable.
Can the 74LCX06MTC be used as a direct drop-in replacement for the 74LCX04MTCX in a push-pull application?
Not without design changes. The 74LCX06MTC has open-drain outputs and cannot source current to drive a logic high. A pull-up resistor must be added to each output, and the resulting RC rise time, power consumption, and logic-high voltage levels must be validated against the target design requirements.
What are the recommended operating voltage ranges for these devices?
Both the 74LCX04MTCX and 74LCX06MTC are specified for operation from 2.0 V to 3.6 V, making them suitable for 3.3 V and 2.5 V logic systems. They are not specified for 5 V VCC operation, although their inputs are tolerant of voltages up to 5.5 V when VCC is within the recommended range.
Do both devices support 5 V tolerant inputs?
Yes. Both the 74LCX04MTCX and 74LCX06MTC feature inputs that are tolerant of voltages up to 5.5 V, independent of the VCC voltage within the recommended operating range. This allows them to interface with 5 V logic without additional level shifting on the input side.
How do the output drive capabilities differ between the 74LCX04MTCX and 74LCX06MTC?
The 74LCX04MTCX provides standard push-pull outputs with specified DC output drive of ±24 mA at VCC = 3.0 V. The 74LCX06MTC provides open-drain outputs with a specified sink current of 24 mA at VCC = 3.0 V, but it does not source current; the logic high level is established by an external pull-up resistor.
What are the typical propagation delay specifications for these devices?
Both the 74LCX04MTCX and 74LCX06MTC have a specified maximum propagation delay of 5.5 ns at VCC = 3.0 V to 3.6 V with a 50 pF load. The 74LCX06MTC propagation delay is measured with a specified pull-up resistor and load capacitance, as defined in the manufacturer datasheet.
Which device is better suited for wired-OR or bus applications?
The 74LCX06MTC is better suited for wired-OR, wired-AND, or shared-bus applications because its open-drain outputs can be tied together with a single pull-up resistor to implement a logical function. The 74LCX04MTCX push-pull outputs cannot be tied together directly, as this can cause contention and excessive current flow.