Part A
74HCT00D
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 1289 PCS
- Package
- SOIC-20
- Series
- Logique - portes et Onduleurs
Replacement verdict
Not a drop-in replacement
The 74HCT00D and 74HCT245D-Q100J are functionally unrelated devices and cannot serve as substitutes for one another. The 74HCT00D is a quad 2-input NAND gate, while the 74HCT245D-Q100J is an octal bus transceiver with 3-state outputs. They differ in logic function, channel count, pinout, and package configuration, making direct replacement impossible without a complete circuit redesign.
Different logic function
Different channel count
Different pinout
Different output type
Parts at a glance
Part B
74HCT245D-Q100J
Nexperia USA Inc.
- Lifecycle
- Active
- Stock
- 6133 PCS
- Package
- SOIC-20
- Series
- Logique - Buffers, lecteurs, récepteurs, émetteurs - récepteurs
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 | 74HCT245D-Q100J | Why it matters |
|---|---|---|---|
| Logic Function | Quad 2-input NAND gate | Octal bus transceiver, 3-state | The logic function defines the fundamental operation of the device; these parts are not functionally interchangeable. |
| Number of Channels | 4 | 8 | Channel count determines how many independent signal paths the device can handle. |
| Output Type | Push-pull | 3-state | 3-state outputs allow bus sharing, while push-pull outputs cannot be tied together. |
| Direction Control | Unidirectional | Bidirectional (DIR pin) | Bidirectional capability enables data flow in both directions, which a fixed-direction gate cannot provide. |
| Package | SO14 (SOIC-14) | SO20 (SOIC-20) | Different package footprints are not drop-in compatible on the same PCB layout. |
| Pin Count | 14 | 20 | Pin count affects board layout and cannot be substituted without redesign. |
| Supply Voltage Range | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Both operate from the same 5 V nominal supply, so voltage compatibility is not a differentiator. |
| Logic Family | HCT (TTL-compatible CMOS) | HCT (TTL-compatible CMOS) | Same logic family ensures compatible input thresholds and output levels. |
| Qualification | Standard commercial | AEC-Q100 automotive qualified | Automotive qualification indicates enhanced reliability and temperature range for harsh environments. |
| Propagation Delay (typ.) | ~9 ns at 5 V | ~10 ns at 5 V | Timing differences can affect signal integrity and system timing margins. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HCT00D | 74HCT245D-Q100J |
|---|---|---|
| Supplier | - | Nexperia USA Inc. |
| Series | 74HCT | Automotive, AEC-Q100, 74HCT |
| Part Status | Obsolete | Active |
| Logic Type | NAND Gate | Transceiver, Non-Inverting |
| Number of Elements | - | 1 |
| Number of Bits per Element | - | 8 |
| 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 ~ 85°C | -40°C ~ 125°C (TA) |
| 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 74HCT245D-Q100J?
The 74HCT00D is a quad 2-input NAND gate, while the 74HCT245D-Q100J is an octal bus transceiver with 3-state outputs. The 74HCT00D performs logic gating, whereas the 74HCT245D-Q100J is designed for bidirectional data bus buffering and signal transmission.
Are the 74HCT00D and 74HCT245D-Q100J pin-compatible?
No. The 74HCT00D is typically supplied in a 14-pin SOIC package, while the 74HCT245D-Q100J is supplied in a 20-pin SOIC package. They have different pin counts and pin functions, so they are not pin-compatible.
Does the 74HCT245D-Q100J meet automotive qualification standards?
Yes. The suffix "-Q100" indicates that the 74HCT245D-Q100J is qualified to the AEC-Q100 standard for automotive applications, as specified in manufacturer documentation. The 74HCT00D is not an automotive-qualified part.
Can the 74HCT00D and 74HCT245D-Q100J operate from the same supply voltage?
Yes. Both devices are members of the 74HCT logic family and are specified for a nominal supply voltage of 5 V, with typical operating ranges as defined in their respective manufacturer datasheets.
What is the difference in output drive capability between these two devices?
The 74HCT00D provides standard HCT-family output drive, typically ±4 mA per output. The 74HCT245D-Q100J provides higher drive, typically ±6 mA per output, as stated in the respective manufacturer datasheets. Designers should verify exact limits from the official datasheets.
Can the 74HCT245D-Q100J be used to replace the 74HCT00D in an existing logic design?
No. The two devices have different logic functions, pin counts, and package sizes. The 74HCT245D-Q100J cannot directly replace the 74HCT00D without a complete redesign of the circuit and PCB layout.
Do both devices feature 3-state outputs?
No. The 74HCT245D-Q100J has 3-state outputs for bus-oriented applications, while the 74HCT00D has standard totem-pole outputs without a high-impedance state.