Part A
74HC00D
Toshiba Halbleiter und Speicher
- Lifecycle
- Active
- Stock
- 4166 Stückzahl
- Package
- SOIC-14
- Series
- Logic-Gates und Wechselrichter
Replacement verdict
Not a drop-in replacement
The 74HC08D and 74HC00D are not functionally interchangeable despite sharing the same 74HC CMOS logic family, SOIC-14 package, and supply voltage range. The 74HC08D contains four 2-input AND gates, while the 74HC00D contains four 2-input NAND gates. These devices implement fundamentally different logic functions, so substituting one for the other will produce incorrect circuit behavior in any design that depends on the specific gate function. Direct replacement is not possible without redesigning the surrounding logic.
Different logic function
Different truth table
Different output polarity
Not pin-compatible in function
Parts at a glance
Part B
74HC08D
Toshiba Halbleiter und Speicher
- Lifecycle
- Active
- Stock
- 5927 Stückzahl
- Package
- SOIC-14
- Series
- Logic-Gates und Wechselrichter
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC08D | 74HC00D | Why it matters |
|---|---|---|---|
| Logic Function | Quad 2-input AND gate | Quad 2-input NAND gate | Defines the Boolean operation performed; AND and NAND are not functionally interchangeable without additional inversion logic. |
| Output Logic Level (Active State) | HIGH when all inputs are HIGH | LOW when all inputs are HIGH | Determines the output polarity for a given input combination, directly affecting circuit behavior. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Both devices operate over the standard HC-family supply range, allowing use in 3.3 V and 5 V systems. |
| Number of Gates | 4 | 4 | Both provide four independent 2-input gates per package, matching pin count and board layout density. |
| Number of Inputs per Gate | 2 | 2 | Both accept two inputs per gate, so pin assignment and fan-in characteristics are comparable. |
| Package | SO14 (SOIC-14) | SO14 (SOIC-14) | Identical package and pin count enable drop-in PCB footprint compatibility. |
| Pin Count | 14 | 14 | Same pin count supports the same socket and routing layout. |
| Propagation Delay (typical at 5 V) | Approximately 9 ns | Approximately 9 ns | Similar timing performance means either device can meet comparable speed requirements in HC-family designs. |
| Output Drive Current | ±4 mA (standard HC) | ±4 mA (standard HC) | Matching drive strength ensures similar fan-out and load-driving capability. |
| Logic Family | 74HC (High-speed CMOS) | 74HC (High-speed CMOS) | Same logic family means compatible input thresholds, noise margins, and interfacing with other HC devices. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC00D | 74HC08D |
|---|---|---|
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Logic Type | NAND Gate | AND Gate |
| Number of Circuits | 4 | 4 |
| Number of Inputs | 2 | 2 |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Current - Quiescent (Max) | 1 µA | 1 µA |
| Current - Output High Low | 5.2mA, 5.2mA | 5.2mA, 5.2mA |
| Logic Level - Low | 0.5V ~ 1.8V | 0.5V ~ 1.8V |
| Logic Level - High | 1.5V ~ 4.2V | 1.5V ~ 4.2V |
| Max Propagation Delay @ V Max CL | 13ns @ 6V, 50pF | 13ns @ 6V, 50pF |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the 74HC08D and 74HC00D?
The 74HC08D contains four independent 2-input AND gates, while the 74HC00D contains four independent 2-input NAND gates. Both are quad 2-input logic gates in the 74HC high-speed CMOS family, but they implement different Boolean functions: AND (output high only when both inputs are high) versus NAND (output low only when both inputs are high).
Are the 74HC08D and 74HC00D pin-compatible?
Yes. Both devices are typically offered in the same SOIC-14 (D) package and share a standard 14-pin quad 2-input gate pinout: pins 1 and 2 are inputs to gate 1, pin 3 is its output, pin 7 is GND, pin 14 is VCC, and the remaining pins follow the same pattern for gates 2 through 4. This common pinout allows them to be used in the same PCB footprint, but the logic function differs.
Can the 74HC08D be used as a direct drop-in replacement for the 74HC00D?
No. Although they may share the same package and pinout, they perform different logic functions. Substituting one for the other without redesigning the surrounding logic will produce incorrect circuit behavior. A direct replacement requires that the intended logic function be identical or that the circuit be modified accordingly.
What are the typical operating voltage and logic level specifications for these devices?
Both the 74HC08D and 74HC00D are 74HC-series CMOS devices typically specified for a supply voltage range of 2.0 V to 6.0 V. They provide CMOS-compatible input thresholds and rail-to-rail output swing, with characteristics such as low quiescent current and standard 74HC propagation delays. Exact limits should be confirmed from the specific manufacturer datasheet.
How do the propagation delays of the 74HC08D and 74HC00D compare?
Both are members of the same 74HC logic family and are fabricated with similar CMOS processes, so their propagation delays are generally comparable and in the same order of magnitude. Actual delay values depend on supply voltage, load capacitance, and temperature, and should be verified from the manufacturer datasheet for the specific device.
Are the 74HC08D and 74HC00D available in the same package options?
Both are commonly available in the SOIC-14 package, designated by the "D" suffix in the part number. They may also be offered in other packages such as TSSOP or DIP by various manufacturers. Package availability can vary by manufacturer, so the specific orderable part number should be checked against the manufacturer or distributor listing.
Which device should be selected for an application requiring an active-low output when both inputs are high?
The 74HC00D should be selected. A NAND gate produces a low output only when both inputs are high, which matches the active-low output condition. The 74HC08D, being an AND gate, produces a high output under that same input condition and would not satisfy the requirement.
Do the 74HC08D and 74HC00D have the same input and output drive characteristics?
As devices in the same 74HC CMOS family, they typically share similar DC input and output characteristics, including standard CMOS input leakage and output drive currents. However, designers should consult the respective manufacturer datasheets to confirm exact IOH, IOL, and input capacitance values, as these can vary slightly between devices and manufacturers.