Part A
74HC126D
Компания Toshiba Semiconductor и Storage
- Lifecycle
- Active
- Stock
- 7257 ПКС
- Package
- SOIC-14
- Series
- Логика - буферы, драйверы, приемники, передатчики
Replacement verdict
Not a drop-in replacement
The 74HC126D and 74HC132D,652 are not functionally interchangeable despite sharing the same 74HC CMOS logic family and SO-14 package. The 74HC126D is a quad non-inverting buffer with 3-state outputs controlled by active-HIGH enable pins, while the 74HC132D,652 is a quad 2-input NAND Schmitt trigger with standard push-pull outputs and no enable function. Their internal logic functions, output drive configurations, and input threshold behavior differ fundamentally, so neither device can directly substitute for the other in an existing design without circuit redesign.
Different logic function
Different output type
Different input threshold
Different enable control
Parts at a glance
Part B
74HC132D,652
Компания NXP Semiconductors
- Lifecycle
- Active
- Stock
- 4717 ПКС
- Series
- Логика - Ворота и инверторы
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC126D | 74HC132D,652 | Why it matters |
|---|---|---|---|
| Logic Function | Quad Buffer with 3-State Outputs | Quad 2-Input NAND Schmitt Trigger | The logic function determines the fundamental behavior of the device; these parts are not functionally interchangeable. |
| Output Type | 3-State | Push-Pull | 3-state outputs allow bus sharing, while push-pull outputs cannot be tied together without contention. |
| Number of Inputs per Gate | 1 (plus enable) | 2 | Input count defines the logic capability and circuit topology each device supports. |
| Schmitt Trigger Input | No | Yes | Schmitt trigger inputs provide hysteresis for noise immunity and slow signal conditioning, which the buffer lacks. |
| Enable Control | Yes (active-high OE per channel) | No | Enable pins allow high-impedance state control for multiplexing and bus applications. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Both operate over the standard HC-family supply range, so power supply compatibility is equivalent. |
| Logic Family | 74HC | 74HC | Same logic family ensures comparable input/output thresholds and drive characteristics. |
| Package | SO-14 (SOIC-14) | SO-14 (SOIC-14) | Identical package and pin count allow the same PCB footprint, though pin functions differ. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Matching temperature ranges ensure equivalent environmental suitability. |
| Mounting Type | Surface Mount | Surface Mount | Same mounting style supports identical assembly processes. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC126D | 74HC132D,652 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Active |
| Series | 74HC | - |
| Logic Type | Buffer, Non-Inverting | - |
| Number of Elements | 4 | - |
| Number of Bits per Element | 1 | - |
| Output Type | 3-State | - |
| Current - Output High Low | 7.8mA, 7.8mA | - |
| Voltage - Supply | 2V ~ 6V | - |
| Operating Temperature | -40°C ~ 125°C (TA) | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the primary functional differences between the 74HC126D and the 74HC132D,652?
The 74HC126D is a quad non-inverting buffer/line driver with 3-state outputs, controlled by active-HIGH output enable pins. The 74HC132D,652 is a quad 2-input NAND Schmitt trigger, providing hysteresis on the inputs for slow or noisy signals. They serve fundamentally different logic functions and are not pin-to-pin functional equivalents.
Are the 74HC126D and 74HC132D,652 pin-compatible in the SO14 package?
Both devices are offered in a 14-pin SO package (SO14), and both use standard 74HC-series pinouts for their respective functions. However, the pin assignments differ: the 74HC126D uses pins as four buffer inputs, four 3-state outputs, and four active-HIGH enable pins, while the 74HC132D,652 uses pins as four pairs of Schmitt-trigger NAND inputs and four outputs. They are not interchangeable without circuit redesign.
Can the 74HC126D drive a bus while the 74HC132D,652 is used for signal conditioning in the same design?
Yes. The 74HC126D is intended for bus driving and 3-state line driving, while the 74HC132D,652 is intended for waveform shaping and noise-immune logic input processing. Using them together is a common architecture: the Schmitt trigger cleans up noisy inputs, and the 3-state buffer drives shared buses.
What supply voltage range do both the 74HC126D and 74HC132D,652 support?
Both are 74HC-family CMOS devices and operate over a supply voltage range of 2.0 V to 6.0 V, with typical operation at 5 V. This wide range supports both 3.3 V and 5 V logic systems, subject to the timing and drive specifications in the respective manufacturer datasheets.
Do both devices have Schmitt-trigger inputs?
No. Only the 74HC132D,652 has Schmitt-trigger inputs with defined hysteresis (typically VT+ and VT- thresholds). The 74HC126D has standard CMOS input thresholds without specified hysteresis, so it is not intended for slow-edge or noisy input signals.
What is the output configuration of each device?
The 74HC126D provides four non-inverting 3-state outputs, each controlled by an active-HIGH enable pin, allowing high-impedance bus sharing. The 74HC132D,652 provides four standard push-pull CMOS outputs from 2-input NAND gates with Schmitt-trigger inputs; it does not have 3-state outputs.
Which device is better suited for debouncing a mechanical switch?
The 74HC132D,652 is better suited for switch debouncing because its Schmitt-trigger inputs provide hysteresis, which rejects contact bounce and slow transitions. The 74HC126D lacks input hysteresis and is not recommended for direct mechanical switch interfacing without external conditioning.
Are the 74HC126D and 74HC132D,652 interchangeable in an existing PCB layout?
No. Although both may use a 14-pin SO package, their internal logic functions, pin assignments, input characteristics, and output types differ. Direct substitution without schematic and layout changes is not valid and may cause malfunction or damage.