Part A
74VHC14MX
Công ty bán dẫn Fairchild
- Lifecycle
- Active
- Stock
- 3753 PCS
- Package
- SOIC-14
- Series
- Logic - Gates and Inverters
Replacement verdict
Not a drop-in replacement
The 74VHC14MX and 74VHC02MX are not functionally interchangeable despite sharing the same VHC logic family and SOIC-14 package. The 74VHC14MX is a hex inverting Schmitt trigger, while the 74VHC02MX is a quad 2-input NOR gate. Their differing logic functions, channel counts, input threshold behavior, and output drive characteristics make direct substitution impossible without circuit redesign.
Different logic function
Different channel count
Different input threshold behavior
Different output drive characteristics
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74VHC14MX | 74VHC02MX | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter with Schmitt Trigger Inputs | Quad 2-Input NOR Gate | Defines the fundamental logic operation; these devices are not functionally interchangeable as they perform entirely different Boolean functions. |
| Number of Circuits | 6 | 4 | Determines how many independent logic elements are available in a single package, affecting board layout and gate count planning. |
| Number of Inputs per Circuit | 1 | 2 | Affects the logic capability of each element; a NOR gate requires two inputs while an inverter requires only one. |
| Schmitt Trigger Input | Yes | No | Schmitt trigger inputs provide hysteresis for noise immunity and slow-edge signal conditioning, which the standard NOR gate does not offer. |
| Output Type | Inverted (Active Low) | NOR Logic Output | The output polarity and logic response differ, directly impacting circuit behavior and signal polarity in the target design. |
| Propagation Delay (typ) | 8.5 ns at 5V | 5.5 ns at 5V | Affects maximum operating frequency and timing margins in synchronous or delay-sensitive circuits. |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | Both support the same VHC operating range, allowing use in 2.5V, 3.3V, and 5V systems. |
| Output Drive Current | ±8 mA at 5V | ±8 mA at 5V | Determines fan-out capability and ability to drive downstream loads or LEDs directly. |
| Package Type | SOIC-14 | SOIC-14 | Identical package footprint allows drop-in PCB compatibility without layout changes. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Both meet industrial temperature requirements, suitable for the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC14MX | 74VHC02MX |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74VHC | 74VHC |
| Part Status | Active | Obsolete |
| Logic Type | Inverter | NOR Gate |
| Number of Circuits | 6 | 4 |
| Number of Inputs | 1 | 2 |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Current - Quiescent (Max) | 2 µA | 2 µA |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Logic Level - Low | 0.9V ~ 1.65V | 0.5V |
| Logic Level - High | 2.2V ~ 3.85V | 1.5V |
| Max Propagation Delay @ V Max CL | 10.6ns @ 5V, 50pF | 7.5ns @ 5V, 50pF |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Features | Schmitt Trigger | - |
Frequently asked questions
What are the primary functional differences between the 74VHC14MX and the 74VHC02MX?
The 74VHC14MX is a hex Schmitt-trigger inverter, providing six independent inverter gates with hysteresis on the inputs. The 74VHC02MX is a quad 2-input NOR gate, providing four independent NOR gates. They differ in logic function, gate count, and input characteristics.
Are the 74VHC14MX and 74VHC02MX pin-compatible in the SOIC-14 package?
No. Although both devices are offered in a 14-pin SOIC package, their pinouts differ. The 74VHC14MX follows the standard hex inverter pinout with inputs on pins 1, 3, 5, 9, 11, and 13 and outputs on pins 2, 4, 6, 8, 10, and 12. The 74VHC02MX follows the standard quad 2-input NOR gate pinout with inputs on pins 1, 2, 5, 6, 8, 9, 12, and 13 and outputs on pins 3, 4, 10, and 11. Direct substitution without PCB redesign is not possible.
Can the 74VHC14MX be used as a direct drop-in replacement for the 74VHC02MX in an existing design?
No. The two devices implement different logic functions and have different pinouts. The 74VHC14MX provides inverting Schmitt-trigger functionality, while the 74VHC02MX provides 2-input NOR logic. A direct drop-in replacement is not feasible without circuit and layout changes.
What are the operating voltage ranges for the 74VHC14MX and 74VHC02MX?
Both devices are members of the VHC family and are specified for a recommended operating supply voltage range of 2.0 V to 5.5 V, per manufacturer datasheets.
Do the 74VHC14MX and 74VHC02MX have the same output drive capability?
Both devices are specified with a standard VHC-family output drive of ±8 mA at 5.0 V VCC, per manufacturer datasheets. However, actual output current should always be verified against the specific manufacturer datasheet for the exact ordering part number.
Which device is better suited for debouncing a noisy input signal?
The 74VHC14MX is better suited for debouncing or cleaning up noisy input signals because it is a Schmitt-trigger inverter with defined hysteresis thresholds (typically VT+ and VT−). The 74VHC02MX is a standard CMOS NOR gate without Schmitt-trigger inputs and does not provide the same noise immunity or hysteresis behavior.
Are the 74VHC14MX and 74VHC02MX available in the same package options?
Both devices are commonly available in 14-pin SOIC (MX suffix) and TSSOP packages from major manufacturers. Package availability may vary by manufacturer and distributor, so the specific ordering part number should be checked against the manufacturer datasheet or authorized distributor listing.
What is the maximum operating temperature range for the 74VHC14MX and 74VHC02MX?
Both devices are typically specified for an operating free-air temperature range of −40 °C to +85 °C for industrial-grade versions, and −40 °C to +125 °C for automotive-grade versions where offered. The exact rating depends on the manufacturer and the specific ordering part number, and should be confirmed from the official datasheet.