Part A
74HC03D
도시바 반도체 및 스토리지
- Lifecycle
- Active
- Stock
- 3334 PCS
- Package
- SOIC-14
- Series
- 로직 - 도어 및 인버터
Replacement verdict
Not a drop-in replacement
The 74HC03D and 74HC02D,652 are not functionally interchangeable despite sharing the same 74HC CMOS logic family and SO-14 package. The 74HC03D provides open-drain outputs requiring external pull-up resistors, while the 74HC02D,652 features standard push-pull outputs. This fundamental output architecture difference, combined with divergent logic functions and drive characteristics, makes direct substitution inadvisable without circuit redesign.
Different output type
Different logic function
External pull-up may be required
Different drive characteristics
Parts at a glance
Part B
74HC02D,652
은지포미국주식회사
- Lifecycle
- Active
- Stock
- 9852 PCS
- Series
- 로직 - 도어 및 인버터
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 | 74HC02D,652 | Why it matters |
|---|---|---|---|
| Logic Function | Quad 2-input NAND gate with open-drain outputs | Quad 2-input NOR gate | The logic function determines the boolean operation performed; NAND and NOR are not functionally interchangeable in a circuit. |
| Output Type | Open-drain | Push-pull (totem-pole) | Open-drain outputs require external pull-up resistors and allow wired-AND configurations, while push-pull outputs drive both high and low actively. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | The supply voltage range defines the compatible power rails and logic levels for the device. |
| Logic Family | HC (High-speed CMOS) | HC (High-speed CMOS) | The logic family determines input thresholds, noise immunity, and compatibility with other logic devices. |
| Number of Gates | 4 | 4 | The gate count affects how many independent logic operations can be implemented in a single package. |
| Number of Inputs per Gate | 2 | 2 | The number of inputs per gate determines the fan-in and the complexity of logic functions that can be realized. |
| Propagation Delay (typical at 5 V) | 9 ns | 9 ns | Propagation delay affects the maximum operating frequency and timing margins in digital circuits. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | The operating temperature range indicates the environments in which the device can reliably function. |
| Package Type | SO14 (SOIC-14) | SO14 (SOIC-14) | The package type determines the PCB footprint and assembly compatibility. |
| Mounting Type | Surface Mount | Surface Mount | The mounting type must match the board assembly process and available footprint. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC03D | 74HC02D,652 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Logic Type | NAND Gate | NOR Gate |
| Number of Circuits | 4 | 4 |
| Number of Inputs | 2 | 2 |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Current - Quiescent (Max) | 1 µA | 2 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 | 15ns @ 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 74HC02D,652?
The 74HC03D contains four 2-input NAND gates with open-drain outputs, while the 74HC02D,652 contains four 2-input NOR gates with standard push-pull CMOS outputs. The logic function and output stage type are therefore different, so they are not functionally interchangeable.
Are the 74HC03D and 74HC02D,652 pin-compatible?
Both devices are typically offered in a 14-pin SOIC package with the same supply and ground pin positions, but the signal pin assignments differ because the internal gate functions and output configurations are not the same. A direct drop-in replacement without PCB or netlist changes is not possible.
Can the 74HC03D drive a load that requires a defined high logic level?
No. The 74HC03D has open-drain outputs, so it can only pull the output low. A defined high level requires an external pull-up resistor or another active pull-up device. The 74HC02D,652 has a standard push-pull output that actively drives both high and low levels.
Do both devices operate from the same supply voltage range?
Yes. Both the 74HC03D and the 74HC02D,652 are 74HC-family CMOS devices and are specified for a nominal supply voltage range of 2.0 V to 6.0 V, with 5 V being a common operating point. Always confirm the exact limits in the specific manufacturer datasheet.
Which device is better for wired-OR or open-drain bus applications?
The 74HC03D is the appropriate choice for wired-OR or open-drain bus configurations because its open-drain NAND outputs can be tied together with a single pull-up resistor. The 74HC02D,652 push-pull outputs must not be tied together directly, as contention can occur.
Are the propagation delays of the 74HC03D and 74HC02D,652 the same?
No. Propagation delay depends on the logic function, output stage, load capacitance, and supply voltage. The 74HC03D open-drain output typically has a longer low-to-high transition when driving a capacitive load through a pull-up resistor, while the 74HC02D,652 push-pull output provides more symmetric rise and fall times. Consult the respective datasheets for verified timing values.
Can the 74HC02D,652 be used as a direct substitute for the 74HC03D in an existing design?
No. The 74HC02D,652 implements NOR logic with a push-pull output, whereas the 74HC03D implements NAND logic with an open-drain output. Substitution would change both the logic function and the output drive behavior, so the circuit would not operate as originally designed.
What package options are available for these devices?
The 74HC03D is commonly supplied in a 14-pin SOIC package, and the 74HC02D,652 is also commonly supplied in a 14-pin SOIC package. Other package variants may exist depending on the manufacturer, so the exact orderable part number and datasheet should be checked before design release.