Part A
74HC00D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 4166 PCS
- Package
- SOIC-14
- Series
- Logic - Gates and Inverters
Replacement verdict
Not a drop-in replacement
The 74HC03D and 74HC00D are not functionally interchangeable despite sharing the same 14-pin SOIC footprint and 74HC logic family. The 74HC03D features open-drain outputs requiring external pull-up resistors, while the 74HC00D provides standard push-pull CMOS outputs. This fundamental output architecture difference affects drive capability, power consumption, and circuit design, making direct substitution inadvisable without schematic modification.
Different output type
External pull-up required
Different drive strength
Different logic function
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC03D | 74HC00D | Why it matters |
|---|---|---|---|
| Logic Function | Quad 2-input NAND with open-drain outputs | Quad 2-input NAND with push-pull outputs | Defines the fundamental logic operation and output stage; open-drain vs push-pull changes how the output can drive loads and interface with other logic. |
| Output Type | Open-drain | Push-pull (CMOS) | Open-drain outputs require an external pull-up resistor and allow wired-OR/AND connections, while push-pull outputs drive both high and low actively without external components. |
| Output Drive Current (IOH/IOL) | IOL = 4 mA (VOL = 0.33 V); IOH not applicable (open-drain) | IOH = -4 mA, IOL = 4 mA | Determines the fan-out and ability to drive LEDs, relays, or other logic inputs; open-drain devices cannot source current. |
| Propagation Delay (tPD) | Typical 9 ns at 4.5 V, 25 °C | Typical 9 ns at 4.5 V, 25 °C | Affects maximum operating frequency and timing margins in synchronous systems; similar delays allow comparable speed performance. |
| Supply Voltage Range (VCC) | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Defines compatibility with 3.3 V and 5 V logic systems; identical ranges ensure interchangeability in mixed-voltage designs. |
| Input Clamp Diodes | Yes (standard HC input protection) | Yes (standard HC input protection) | Protects inputs from voltage transients and allows level shifting with series resistors; both devices share the same input structure. |
| Package | SO14 (D package) | SO14 (D package) | Physical footprint and pinout must match for direct PCB replacement; identical SO14 packages allow drop-in substitution. |
| Pin Count | 14 | 14 | Pin count and assignment determine whether the part can be swapped without layout changes; both use the standard 14-pin NAND gate pinout. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Ensures reliable operation in industrial and automotive environments; identical ranges mean no thermal derating differences. |
| Quiescent Supply Current (ICC) | Max 2 µA at 6 V, 25 °C | Max 2 µA at 6 V, 25 °C | Low standby current is critical for battery-powered and low-power designs; matching values indicate similar power efficiency. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC00D | 74HC03D |
|---|---|---|
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Logic Type | NAND Gate | NAND 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 |
| 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 |
| Features | - | Open Drain |
Frequently asked questions
What is the main functional difference between the 74HC03D and the 74HC00D?
The 74HC03D contains four 2-input NAND gates with open-drain outputs, while the 74HC00D contains four 2-input NAND gates with standard push-pull CMOS outputs. The 74HC03D requires external pull-up resistors for logic-high outputs, whereas the 74HC00D drives both logic-high and logic-low levels directly.
Are the 74HC03D and 74HC00D pin-compatible?
Yes, both devices are typically offered in the same SO14 package with identical pinouts: pins 1, 2, 4, 5, 9, 10, 12, and 13 are the gate inputs; pins 3, 6, 8, and 11 are the gate outputs; pin 7 is GND; and pin 14 is VCC. This pin compatibility allows the 74HC03D to be used in a 74HC00D socket, provided the open-drain output behavior is acceptable for the circuit.
Can the 74HC03D directly replace the 74HC00D in an existing design?
Not without circuit review. The 74HC03D has open-drain outputs, so any node that relied on the 74HC00D actively driving a logic high will float unless a pull-up resistor is added. The 74HC00D can replace the 74HC03D only if the open-drain behavior and external pull-ups of the original 74HC03D circuit are no longer required or are otherwise satisfied.
What are the output drive characteristics of the 74HC03D compared with the 74HC00D?
The 74HC00D provides standard CMOS push-pull outputs that sink and source current symmetrically within the device ratings. The 74HC03D provides open-drain outputs that can sink current but cannot source current; the logic-high level is established by an external pull-up resistor. Therefore, the 74HC03D is useful for wired-OR/wired-AND configurations and for level shifting, while the 74HC00D is used for conventional logic driving.
Do both the 74HC03D and 74HC00D operate over the same supply voltage range?
Yes, both are 74HC-series CMOS devices and are specified for a nominal supply voltage range of 2.0 V to 6.0 V, with 5 V being the most common operating condition. Actual limits and timing parameters should always be confirmed from the specific manufacturer datasheet.
Which device is better for interfacing with a shared bus or wired-logic configuration?
The 74HC03D is better suited for shared-bus or wired-logic configurations because its open-drain outputs allow multiple outputs to be tied together with a single pull-up resistor, producing a wired-AND function. The 74HC00D push-pull outputs cannot be tied together directly without risking contention and excessive current.
Are the 74HC03D and 74HC00D interchangeable in terms of logic function?
Both devices implement four independent 2-input NAND functions, so the Boolean logic is identical. The difference is electrical: the 74HC03D has open-drain outputs and the 74HC00D has push-pull outputs. Interchangeability therefore depends on whether the output stage requirements of the target circuit are met.
What package type is indicated by the "D" suffix on both the 74HC03D and 74HC00D?
The "D" suffix in these part numbers typically denotes a small-outline IC package, commonly SO14 or SOIC-14, depending on the manufacturer. Package dimensions, thermal characteristics, and exact ordering codes should be verified from the specific manufacturer datasheet before layout or procurement.