Part A
74HCT04D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 4496 PCS
- Package
- SOIC-16
- Series
- Lógica - Gates e Inverters
Replacement verdict
Not a drop-in replacement
The 74HCT04D and 74HCT125D-Q100J are not functionally interchangeable. The 74HCT04D is a hex inverting gate with unbuffered outputs, while the 74HCT125D-Q100J is a quad non-inverting buffer featuring 3-state outputs and is qualified to the automotive AEC-Q100 standard. These differences in logic function, output type, channel count, and qualification level prevent direct substitution without circuit redesign.
Different logic function
Different output type
Different channel count
Different qualification level
Parts at a glance
Part B
74HCT125D-Q100J
Nexperia USA Inc.
- Lifecycle
- Active
- Stock
- 9544 PCS
- Package
- SOIC-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 | 74HCT04D | 74HCT125D-Q100J | Why it matters |
|---|---|---|---|
| Logic Function | Hex inverter (6 independent inverters) | Quad buffer with 3-state outputs | The core logic function differs, so these parts are not functionally interchangeable in a circuit. |
| Number of Channels | 6 | 4 | Channel count affects how many signals can be processed per package. |
| Output Type | Push-pull (inverting) | 3-state (non-inverting) | 3-state outputs allow bus sharing, while push-pull outputs cannot be tied together. |
| Output Enable Control | None | Yes (active-low OE per channel) | Enable pins allow the outputs to be placed in high-impedance state for multiplexed buses. |
| Logic Polarity | Inverting | Non-inverting | Polarity determines whether the output is the complement or copy of the input signal. |
| Supply Voltage Range | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Both operate from the standard 5 V TTL-compatible supply, so power rails are compatible. |
| Logic Family | HCT (TTL-compatible CMOS) | HCT (TTL-compatible CMOS) | Same logic family ensures compatible input thresholds and output drive characteristics. |
| Package | SO14 (SOIC-14) | SO14 (SOIC-14) | Package footprint and pin count affect PCB layout and drop-in compatibility. |
| Qualification | Standard commercial grade | AEC-Q100 automotive qualified | Automotive qualification indicates enhanced reliability and temperature range for harsh environments. |
| Propagation Delay (typical) | ~11 ns at 5 V | ~14 ns at 5 V | Timing differences can affect signal integrity and maximum operating frequency in synchronous designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HCT04D | 74HCT125D-Q100J |
|---|---|---|
| Supplier | - | Nexperia USA Inc. |
| Series | 74HCT | Automotive, AEC-Q100, 74HCT |
| Part Status | Active | Active |
| Logic Type | Inverter | Buffer, Non-Inverting |
| Number of Elements | - | 4 |
| Number of Bits per Element | - | 1 |
| Output Type | - | 3-State |
| Current - Output High Low | 4mA, 4mA | 6mA, 6mA |
| Voltage - Supply | 4.5V ~ 5.5V | 4.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Circuits | 6 | - |
| Number of Inputs | 1 | - |
| Current - Quiescent (Max) | 1 µA | - |
| Logic Level - Low | 0.8V | - |
| Logic Level - High | 2V | - |
| Max Propagation Delay @ V Max CL | 16ns @ 5.5V, 50pF | - |
Frequently asked questions
What are the primary functional differences between the 74HCT04D and 74HCT125D-Q100J?
The 74HCT04D is a hex inverter with six independent NOT gates, while the 74HCT125D-Q100J is a quad buffer with 3-state outputs. The 74HCT04D inverts the input signal, whereas the 74HCT125D-Q100J provides non-inverting buffering with an output enable control for each channel.
Are the 74HCT04D and 74HCT125D-Q100J pin-compatible?
No. The 74HCT04D is typically supplied in a 14-pin SOIC package, while the 74HCT125D-Q100J is supplied in a 14-pin SOIC package but with a different pinout. The 74HCT04D has six inverters with inputs and outputs on pins 1–12 and power on pins 7 and 14. The 74HCT125D-Q100J has four buffers with individual output enable pins, and its pin assignments differ, so they are not drop-in replacements.
Can the 74HCT04D be used as a direct substitute for the 74HCT125D-Q100J in an existing design?
No. The 74HCT04D lacks 3-state outputs and output enable control, and it inverts the signal. The 74HCT125D-Q100J provides non-inverting buffering with high-impedance output states. Substitution would require logic redesign and validation against the target application.
What are the supply voltage and logic level specifications for both devices?
Both the 74HCT04D and 74HCT125D-Q100J operate from a nominal 5 V supply and are TTL-compatible on their inputs. The 74HCT family supports a supply voltage range typically from 4.5 V to 5.5 V. These parameters are consistent with the HCT logic family standard.
Does the 74HCT125D-Q100J have any automotive qualification that the 74HCT04D lacks?
Yes. The 74HCT125D-Q100J carries the Q100 suffix, indicating it is qualified to the AEC-Q100 standard for automotive applications. The 74HCT04D, as a standard logic device, does not carry this automotive qualification unless a specific Q100 variant is ordered.
What is the difference in output drive capability between the 74HCT04D and 74HCT125D-Q100J?
Both devices are standard HCT-family logic parts. The 74HCT04D and 74HCT125D-Q100J typically provide symmetrical output drive of ±4 mA at 5 V, which is standard for the 74HCT series. Actual drive strength should be confirmed from the specific manufacturer datasheet.
Which device is more suitable for bus-oriented applications?
The 74HCT125D-Q100J is more suitable for bus-oriented applications because it features 3-state outputs that can be placed in a high-impedance state, allowing multiple devices to share a common bus. The 74HCT04D has standard totem-pole outputs and cannot be tri-stated.
Are the propagation delays of the 74HCT04D and 74HCT125D-Q100J the same?
No. The 74HCT04D and 74HCT125D-Q100J have different internal architectures, so their propagation delays differ. The 74HCT04D typically has a propagation delay in the range of 8 ns to 15 ns at 5 V, while the 74HCT125D-Q100J typically has a propagation delay in the range of 10 ns to 18 ns at 5 V. Exact values depend on the manufacturer and load conditions.