Part A
74HCT00D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 1289 PCS
- Package
- SOIC-20
- Series
- Lógica - Gates e Inverters
Replacement verdict
Not a drop-in replacement
The 74HCT00D and 74HCT123D-Q100J are not functionally interchangeable. The 74HCT00D is a quad 2-input NAND gate, while the 74HCT123D-Q100J is a dual retriggerable monostable multivibrator. They differ in logic function, channel count, output behavior, and package configuration, so the 74HCT123D-Q100J cannot directly replace the 74HCT00D in existing designs.
Different logic function
Different channel count
Different output behavior
Different package type
Parts at a glance
Part B
74HCT123D-Q100J
Nexperia USA Inc.
- Lifecycle
- Active
- Stock
- 7163 PCS
- Package
- SOIC-16
- Series
- Lógica - Multivibradores
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HCT00D | 74HCT123D-Q100J | Why it matters |
|---|---|---|---|
| Logic Function | Quad 2-input NAND gate | Dual retriggerable monostable multivibrator with reset | The logic function determines the fundamental behavior of the device; these parts perform completely different operations and are not functionally interchangeable. |
| Number of Gates / Channels | 4 gates | 2 channels | The channel count affects how many independent signal paths are available in a design. |
| Output Type | Push-pull (standard CMOS totem-pole) | Push-pull with complementary outputs (Q and Qbar) | Output configuration determines how the device can drive downstream loads and whether complementary signals are available. |
| Propagation Delay (typical) | ~9 ns at 5 V | ~25 ns at 5 V | Propagation delay affects timing margins and maximum operating frequency in a system. |
| Supply Voltage Range | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Both operate in the standard HCT 5 V range, so supply compatibility is not a differentiator here. |
| Package | SO14 (SOIC-14) | SO16 (SOIC-16) | Different pin counts and package footprints prevent direct drop-in replacement on the same PCB pad layout. |
| Pin Count | 14 | 16 | Pin count mismatch means the devices cannot share the same socket or footprint. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Both meet automotive/industrial temperature requirements, so thermal range is not a differentiator. |
| Automotive Qualification | Not AEC-Q100 qualified | AEC-Q100 qualified | AEC-Q100 qualification is required for automotive applications and indicates enhanced reliability screening. |
| Trigger / Retrigger Capability | Not applicable (combinational logic) | Retriggerable monostable | Retriggerability allows the output pulse to be extended by additional input pulses, a function unavailable in the NAND gate. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HCT00D | 74HCT123D-Q100J |
|---|---|---|
| Supplier | - | Nexperia USA Inc. |
| Series | 74HCT | Automotive, AEC-Q100, 74HCT |
| Part Status | Obsolete | Active |
| Logic Type | NAND Gate | Monostable |
| Independent Circuits | - | 2 |
| Schmitt Trigger Input | - | Yes |
| Propagation Delay | - | 65 ns |
| Current - Output High Low | 4mA, 4mA | 4mA, 4mA |
| Voltage - Supply | 4.5V ~ 5.5V | 4.5 V ~ 5.5 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Circuits | 4 | - |
| Number of Inputs | 2 | - |
| Current - Quiescent (Max) | 1 µA | - |
| Logic Level - Low | 0.8V | - |
| Logic Level - High | 2V | - |
| Max Propagation Delay @ V Max CL | 17ns @ 5.5V, 50pF | - |
Frequently asked questions
What are the primary functional differences between the 74HCT00D and the 74HCT123D-Q100J?
The 74HCT00D is a quad 2-input NAND gate, while the 74HCT123D-Q100J is a dual retriggerable monostable multivibrator with reset. The 74HCT00D performs combinational logic, whereas the 74HCT123D-Q100J generates output pulses of a specified duration determined by external timing components.
Are the 74HCT00D and 74HCT123D-Q100J pin-compatible?
No. The 74HCT00D is typically supplied in a 14-pin SOIC package, and the 74HCT123D-Q100J is supplied in a 16-pin SOIC package. They have different pin counts and pin functions, so they are not pin-compatible.
Can the 74HCT00D be used as a direct substitute for the 74HCT123D-Q100J in an existing design?
No. The two devices have different logic functions, pinouts, and package sizes. A direct substitution is not possible without redesigning the circuit and PCB layout.
What is the operating voltage range for both the 74HCT00D and the 74HCT123D-Q100J?
Both devices are HCT-family logic components and operate over a supply voltage range of 4.5 V to 5.5 V, with typical operation at 5 V.
Does the 74HCT123D-Q100J have any automotive qualification that the 74HCT00D lacks?
Yes. The 74HCT123D-Q100J carries the Q100 suffix, indicating it is qualified to the AEC-Q100 standard for automotive applications. The 74HCT00D is a standard commercial-grade logic device and is not AEC-Q100 qualified.
What timing components are required for the 74HCT123D-Q100J, and does the 74HCT00D require them?
The 74HCT123D-Q100J requires external resistors and capacitors connected to its timing pins to set the output pulse width. The 74HCT00D is a pure logic gate and does not require any external timing components.
What are the output drive capabilities of the 74HCT00D and the 74HCT123D-Q100J?
Both devices provide standard HCT-family output drive, typically ±4 mA at 5 V. For exact output current ratings, refer to the respective manufacturer datasheets, as values may vary slightly between suppliers.
Are both the 74HCT00D and the 74HCT123D-Q100J available in SOIC packages?
Yes. The 74HCT00D is commonly available in a 14-pin SOIC package, and the 74HCT123D-Q100J is commonly available in a 16-pin SOIC package. Both use the SOIC form factor but differ in pin count.