Part A
74HC238D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 5394 PCS
- Package
- SOIC-16
- Series
- Lógica - Conmutadores de sinais, Multiplexers, Decodificadores
Replacement verdict
Not a drop-in replacement
The 74HC238D and 74HC251D-Q100J are functionally dissimilar logic ICs: one is a 3-to-8 decoder/demultiplexer and the other is an 8-input multiplexer with 3-state outputs. They differ in logic function, output type, channel configuration, and package/pinout, so neither can directly substitute for the other in an existing design without circuit redesign.
Different logic function
Different output type
Different channel configuration
Different package and pinout
Parts at a glance
Part B
74HC251D-Q100J
Nexperia USA Inc.
- Lifecycle
- Active
- Stock
- 6040 PCS
- Package
- SOIC-16
- Series
- Lógica - Conmutadores de sinais, Multiplexers, Decodificadores
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC238D | 74HC251D-Q100J | Why it matters |
|---|---|---|---|
| Function | 3-to-8 Line Decoder / Demultiplexer | 8-Input Multiplexer with 3-State Outputs | These devices perform fundamentally different logic functions, so they are not functionally substitutable in a circuit. |
| Logic Type | Decoder/Demultiplexer | Multiplexer | The logic type determines the input-to-output mapping and the role the IC plays in a design. |
| Number of Outputs | 8 | 1 | Output count affects how many downstream loads or signal paths the device can drive. |
| Number of Inputs | 3 (address) plus enable inputs | 8 data plus select inputs | Input count and type determine the selection/addressing scheme and overall interface complexity. |
| Output Type | Active-low outputs | 3-state | Output type affects bus sharing, drive capability, and whether outputs can be tied together. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | Both support the standard HC family supply range, allowing use in similar logic-level systems. |
| Package | SOIC-16 | SOIC-16 | Matching package and pin count can simplify PCB layout, though pin functions still differ. |
| Qualification | Standard commercial grade | AEC-Q100 automotive qualified | Automotive qualification indicates enhanced reliability and testing for harsh environments. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Similar temperature ratings mean both can operate in comparable industrial temperature environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC238D | 74HC251D-Q100J |
|---|---|---|
| Supplier | - | Nexperia USA Inc. |
| Series | 74HC | Automotive, AEC-Q100, 74HC |
| Part Status | Active | Active |
| Type | Decoder/Demultiplexer | Multiplexer |
| Circuit | 1 x 3:8 | 1 x 8:1 |
| 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 ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |