Part A
74HC123D
恩智浦美國股份有限公司。
- Lifecycle
- Active
- Stock
- 3320 件
- Package
- SOIC-16
- Series
- 邏輯-多振動器
Replacement verdict
Not a drop-in replacement
The 74HC123D and 74HC154D,653 serve fundamentally different logic functions and cannot be used interchangeably in existing designs. The 74HC123D is a dual retriggerable monostable multivibrator for pulse generation, while the 74HC154D,653 is a 4-to-16 line decoder/demultiplexer for address decoding. Their pinouts, input/output configurations, and functional behavior are entirely incompatible, requiring a complete circuit redesign rather than a direct substitution.
Different logic function
Different input/output configuration
Different pinout
Different application purpose
Parts at a glance
Part B
74HC154D,653
恩智浦美國股份有限公司。
- Lifecycle
- Active
- Stock
- 4133 件
- Package
- SOIC-24
- Series
- 邏輯-訊號開關、多工器、解碼器
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC123D | 74HC154D,653 | Why it matters |
|---|---|---|---|
| Function | Dual retriggerable monostable multivibrator with reset | 4-to-16 line decoder/demultiplexer | These devices perform completely different logic functions, so they are not functionally substitutable in a circuit. |
| Logic Type | Monostable multivibrator | Decoder/demultiplexer | The logic type determines the signal-processing behavior and cannot be interchanged between these parts. |
| Number of Circuits | 2 | 1 | The number of independent channels affects how many signals can be processed per package. |
| Number of Outputs | 2 | 16 | Output count determines how many loads or logic lines the device can drive. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | Both parts operate over the same HC-family supply range, so voltage compatibility is not a differentiator. |
| Propagation Delay | Typically 25 ns at 5 V | Typically 20 ns at 5 V | Propagation delay affects timing margins and maximum operating speed in the target design. |
| Output Current | ±4 mA | ±4 mA | Drive current determines the ability to interface with other logic or small loads. |
| Package | SO-16 | SO-24 | Different package sizes and pin counts prevent direct drop-in replacement on the same PCB footprint. |
| Pin Count | 16 | 24 | Pin count mismatch means the devices cannot share the same socket or layout. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Both parts support the same industrial temperature range, so thermal compatibility is equivalent. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC123D | 74HC154D,653 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Type | - | Decoder/Demultiplexer |
| Circuit | - | 1 x 4:16 |
| Independent Circuits | 2 | 1 |
| Current - Output High Low | 5.2mA, 5.2mA | 5.2mA, 5.2mA |
| Voltage Supply Source | - | Single Supply |
| Voltage - Supply | 2 V ~ 6 V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Logic Type | Monostable | - |
| Schmitt Trigger Input | Yes | - |
| Propagation Delay | 40 ns | - |
Frequently asked questions
What are the primary functions of the 74HC123D and the 74HC154D,653?
The 74HC123D is a dual retriggerable monostable multivibrator that generates output pulses of a specified duration determined by external timing components. The 74HC154D,653 is a 4-to-16 line decoder/demultiplexer that accepts a 4-bit binary address and activates one of sixteen mutually exclusive outputs.
Can the 74HC123D and 74HC154D,653 be used interchangeably in a design?
No. They perform fundamentally different logic functions. The 74HC123D provides monostable pulse generation, while the 74HC154D,653 performs address decoding and demultiplexing. They are not pin-compatible or functionally equivalent and cannot be substituted for one another.
What are the package and pin count differences between the 74HC123D and the 74HC154D,653?
The 74HC123D is typically supplied in a 16-pin SOIC package. The 74HC154D,653 is supplied in a 24-pin SOIC package. The difference in pin count reflects their distinct internal logic and I/O requirements.
What supply voltage range do the 74HC123D and 74HC154D,653 support?
Both devices are members of the 74HC high-speed CMOS family and operate over a nominal supply voltage range of 2.0 V to 6.0 V, with characterized performance typically specified at 4.5 V and 6.0 V.
How does the output drive capability compare between the 74HC123D and the 74HC154D,653?
Both devices are standard 74HC CMOS logic parts. Their outputs are specified with standard 74HC DC output characteristics, typically capable of driving CMOS inputs and low-power Schottky TTL loads within the rated supply voltage and temperature range. Detailed IOH and IOL limits should be taken from the respective manufacturer datasheets.
What are the typical applications for the 74HC123D versus the 74HC154D,653?
The 74HC123D is used for pulse shaping, timing delays, and retriggerable one-shot generation. The 74HC154D,653 is used for memory address decoding, I/O port selection, and demultiplexing a single data input to one of sixteen outputs.
Are the 74HC123D and 74HC154D,653 compatible with standard 74HC logic levels?
Yes. Both devices are 74HC family parts and use standard high-speed CMOS input and output voltage thresholds, allowing direct interfacing with other 74HC, HCT, and many TTL-compatible logic devices when operated at the same supply voltage.
What timing or control inputs distinguish the 74HC123D from the 74HC154D,653?
The 74HC123D has trigger inputs, a clear input, and external RC timing pins for each monostable channel. The 74HC154D,653 has four address inputs, two enable inputs, and sixteen decoded outputs, with no timing or retrigger capability.