Part A
74HC157D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 7197 PCS
- Package
- SOIC-16
- Series
- Logic - Signal Switches, Multiplexers, Decoders
Replacement verdict
Not a drop-in replacement
The 74HC157D and 74HC154D,652 are functionally unrelated logic ICs and cannot serve as substitutes for one another. The 74HC157D is a quad 2-input multiplexer, while the 74HC154D,652 is a 4-to-16 line decoder/demultiplexer. Their logic functions, input/output configurations, channel counts, and pinouts differ fundamentally, making direct replacement impossible without complete circuit redesign.
Different logic function
Different channel count
Different input/output configuration
Different pinout
Parts at a glance
Part B
74HC154D,652
NXP USA Inc.
- Lifecycle
- Active
- Stock
- 2528 PCS
- Package
- SOIC-24
- Series
- Logic - Signal Switches, Multiplexers, Decoders
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC157D | 74HC154D,652 | Why it matters |
|---|---|---|---|
| Function | Quad 2-input multiplexer | 4-to-16 line decoder/demultiplexer | These devices perform fundamentally different logic functions, so they are not functionally substitutable in a circuit. |
| Logic Type | Multiplexer (MUX) | Decoder/Demultiplexer | The logic type determines the signal routing behavior and the role the IC plays in a design. |
| Number of Circuits | 4 | 1 | The number of independent logic circuits affects how many signals can be processed simultaneously. |
| Number of Inputs per Circuit | 2 | 4 | Input count per circuit defines the selection capability and address width of the device. |
| Number of Outputs | 4 | 16 | Output count determines how many downstream lines can be driven or selected. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | Both parts share the HC-family supply range, so voltage compatibility is not a differentiator. |
| Propagation Delay | Typically around 14 ns at 5 V | Typically around 20 ns at 5 V | Propagation delay affects timing margins and maximum operating speed in synchronous designs. |
| Output Drive Current | ±4 mA typical at 5 V | ±4 mA typical at 5 V | Drive current determines the ability to interface with other logic gates or loads. |
| Package Type | SOIC-16 | SOIC-24 | Package footprint and pin count must match the PCB layout for physical compatibility. |
| Pin Count | 16 | 24 | Different pin counts mean the devices cannot be dropped into the same socket or footprint. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC157D | 74HC154D,652 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Type | Multiplexer | Decoder/Demultiplexer |
| Circuit | 4 x 2:1 | 1 x 4:16 |
| Independent Circuits | 1 | 1 |
| Current - Output High Low | 5.2mA, 5.2mA | 5.2mA, 5.2mA |
| Voltage Supply Source | Single Supply | Single Supply |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the 74HC157D and the 74HC154D,652?
The 74HC157D is a quad 2-input multiplexer that selects one of two 4-bit data sources based on a common select input. The 74HC154D,652 is a 4-to-16 line decoder/demultiplexer that decodes a 4-bit binary address into one of 16 mutually exclusive active-LOW outputs. They perform fundamentally different logic functions and are not interchangeable.
Do the 74HC157D and 74HC154D,652 have the same pin count and package type?
Both devices are typically offered in a 16-pin SOIC package (the "D" suffix in 74HC157D and the "652" suffix in 74HC154D,652 denotes SOIC packaging from Nexperia). However, their pinouts and internal functions differ, so they cannot be substituted solely based on package similarity.
Can the 74HC157D be used to replace the 74HC154D,652 in an existing design?
No. The 74HC157D is a multiplexer, while the 74HC154D,652 is a decoder/demultiplexer. Their logic functions, truth tables, and output configurations are different. A direct replacement is not possible without redesigning the surrounding circuitry.
What are the output drive characteristics of these two devices?
Both are HC-family CMOS devices typically specified with a standard output drive of ±4 mA at 5 V VCC. The 74HC157D provides active-HIGH outputs, while the 74HC154D,652 provides active-LOW outputs. Designers must account for the output polarity difference when interfacing with other logic.
Are the 74HC157D and 74HC154D,652 compatible with 3.3 V logic systems?
Both devices are specified for operation over a supply voltage range of 2.0 V to 6.0 V, which includes 3.3 V. However, input threshold voltages and output levels should be verified against the specific system's logic levels. They are not 5 V-tolerant when powered at 3.3 V unless explicitly stated in the manufacturer datasheet.
What is the propagation delay difference between the 74HC157D and the 74HC154D,652?
At 5 V VCC and 25 °C, the 74HC157D typically exhibits a propagation delay of approximately 11 ns to 14 ns depending on the path. The 74HC154D,652 typically exhibits a propagation delay of approximately 15 ns to 20 ns. Exact values vary by manufacturer and load conditions; consult the specific datasheet for guaranteed limits.
Which device is better suited for expanding I/O lines in a microcontroller system?
The 74HC154D,652 is typically used for address decoding or expanding outputs by selecting one of 16 lines. The 74HC157D is used for data routing or multiplexing two 4-bit sources onto a single 4-bit bus. The choice depends on whether the application requires selection (decoding) or data path switching (multiplexing).
Do both devices support the same operating temperature range?
Yes, both the 74HC157D and 74HC154D,652 are typically specified for the industrial temperature range of -40 °C to +125 °C or -40 °C to +85 °C depending on the specific manufacturer variant. Always confirm the exact temperature grade from the ordered part number's datasheet.