Part A
74HC151D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 3388 PCS
- Package
- SOIC-16
- Series
- Lógica - Conmutadores de sinais, Multiplexers, Decodificadores
Replacement verdict
Not a drop-in replacement
The 74HC14D,653 and 74HC151D are not functionally interchangeable. The 74HC14D,653 is a hex inverting Schmitt trigger, while the 74HC151D is an 8-to-1 multiplexer. They differ in logic function, input/output configuration, channel count, and pinout, so direct substitution is not possible without a complete circuit redesign.
Different logic function
Different channel count
Different input type
Different pinout
Parts at a glance
Part B
74HC14D,653
Nexperia USA Inc.
- Lifecycle
- Active
- Stock
- 3794 PCS
- Package
- SOIC-14
- Series
- Lógica - Gates e Inverters
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC14D,653 | 74HC151D | Why it matters |
|---|---|---|---|
| Logic Function | Hex inverting Schmitt trigger | 8-input multiplexer (data selector) | The two devices perform fundamentally different logic functions, so they are not functionally interchangeable in a circuit. |
| Number of Channels / Inputs | 6 inverters | 8 data inputs (1 of 8 select) | Channel/input count determines how many signals the device can process, directly affecting circuit architecture and pin usage. |
| Output Type | Inverting Schmitt-trigger output | Complementary outputs (Y and W) | Output configuration affects signal polarity and whether both true and inverted results are available to downstream logic. |
| Schmitt Trigger Input | Yes | No | Schmitt-trigger inputs provide hysteresis for noise immunity and clean edge shaping on slow or noisy signals. |
| Propagation Delay (typical) | ~13 ns at 4.5 V | ~14 ns at 4.5 V | Propagation delay influences maximum operating speed and timing margins in synchronous designs. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | The supply range determines compatibility with 3.3 V and 5 V logic systems and overall design flexibility. |
| Package | SO14 (SOIC-14) | SO16 (SOIC-16) | Different package sizes and pin counts prevent direct drop-in replacement on the same PCB footprint. |
| Pin Count | 14 | 16 | Pin count mismatch means the devices cannot share the same socket or land pattern. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | The temperature range confirms suitability for industrial and automotive-grade environments. |
| Logic Family | 74HC | 74HC | Sharing the same logic family ensures compatible voltage thresholds and drive characteristics when interfacing. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC151D | 74HC14D,653 |
|---|---|---|
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Type | Multiplexer | - |
| Circuit | 1 x 8:1 | - |
| Independent Circuits | 1 | - |
| Current - Output High Low | 5.2mA, 5.2mA | 5.2mA, 5.2mA |
| Voltage Supply Source | Single Supply | - |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Logic Type | - | Inverter |
| Number of Circuits | - | 6 |
| Number of Inputs | - | 1 |
| Features | - | Schmitt Trigger |
| Current - Quiescent (Max) | - | 2 µA |
| Logic Level - Low | - | 0.3V ~ 1.2V |
| Logic Level - High | - | 1.5V ~ 4.2V |
| Max Propagation Delay @ V Max CL | - | 21ns @ 6V, 50pF |
Frequently asked questions
What are the primary functions of the 74HC14D,653 and the 74HC151D?
The 74HC14D,653 is a hex inverting Schmitt trigger, used for signal conditioning and waveform shaping of slow or noisy digital inputs. The 74HC151D is an 8-input multiplexer that selects one of eight data inputs based on a 3-bit binary select code and routes it to a single output.
Can the 74HC14D,653 and 74HC151D be used as direct substitutes for each other?
No. They perform fundamentally different logic functions. The 74HC14D,653 provides inverting Schmitt trigger outputs, while the 74HC151D provides data selection and multiplexing. Substitution would require a complete redesign of the surrounding circuit.
Do the 74HC14D,653 and 74HC151D use the same package and pinout?
Both devices are typically offered in SO-14 packages, but their pinouts and internal functions differ. The 74HC14D,653 contains six inverters with Schmitt trigger inputs, while the 74HC151D contains an 8-to-1 multiplexer with select, enable, and complementary outputs. Pin-to-pin compatibility is not guaranteed.
What are the key electrical differences between the 74HC14D,653 and the 74HC151D?
The 74HC14D,653 features Schmitt trigger inputs with defined positive and negative threshold voltages, providing hysteresis for noise immunity. The 74HC151D has standard CMOS inputs without Schmitt trigger hysteresis and includes select and enable control pins. Both operate over a typical 2 V to 6 V supply range as 74HC-family devices.
Which device is better for cleaning up noisy digital signals?
The 74HC14D,653 is specifically designed for this purpose. Its Schmitt trigger inputs provide hysteresis, which helps convert slow or noisy analog-like signals into clean digital outputs. The 74HC151D does not provide Schmitt trigger input hysteresis and is intended for data selection rather than signal conditioning.
Can the 74HC151D be used to expand the input count of a microcontroller?
Yes. The 74HC151D is an 8-to-1 multiplexer that allows multiple digital signals to be selected and read through a single input line using a 3-bit select code. This makes it suitable for input expansion in microcontroller-based systems.
Are the 74HC14D,653 and 74HC151D compatible with 3.3 V logic systems?
Both devices are 74HC-family parts and typically operate from 2 V to 6 V, so they can be used in 3.3 V systems. However, input voltage thresholds and output drive characteristics should always be verified against the specific manufacturer datasheet for the exact part number and operating conditions.
What are the typical applications for each device?
The 74HC14D,653 is commonly used for debouncing switches, shaping slow waveforms, and conditioning noisy digital inputs. The 74HC151D is commonly used for data multiplexing, input expansion, and selecting one of several digital signals in communication or control systems.