Part A
74ACT125SCX
onsemi
- Lifecycle
- Active
- Stock
- 6699 PCS
- Package
- SOIC-14
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Compatible functional replacement candidate
The 74ACT125SCX and 74ACT125PC are functionally equivalent quad bus buffer gates with 3-state outputs, sharing identical logic function, pin configuration, and AC/DC electrical characteristics. The primary distinction is the package type: the 74ACT125SCX is supplied in a 14-lead SOIC package for surface-mount assembly, while the 74ACT125PC is supplied in a 14-lead PDIP package for through-hole mounting. Designers must verify that the target PCB footprint and assembly process accommodate the selected package before substituting one for the other.
Logic Function
High match
Output Type
High match
Pin Configuration
High match
Package Type
Validation required
Parts at a glance
Part B
74ACT125PC
onsemi
- Lifecycle
- Active
- Stock
- 2658 PCS
- Package
- DIP-14
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74ACT125SCX | 74ACT125PC | Why it matters |
|---|---|---|---|
| Package / Mounting Type | 14-SOIC (Surface Mount) | 14-PDIP (Through-Hole) | Determines PCB footprint, assembly method, and mechanical interchangeability; the two parts are not drop-in replacements for each other. |
| Supplier Device Package | 14-SOIC | 14-PDIP | Confirms the physical package outline used for board layout and socketing. |
| Operating Temperature Range | -40°C to 85°C | -40°C to 85°C | Defines the ambient temperature window for reliable operation; identical ratings support similar thermal environments. |
| Logic Type | Quad Buffer, Non-Inverting, 3-State | Quad Buffer, Non-Inverting, 3-State | Core function must match for functional substitutability; both provide four independent 3-state non-inverting buffers. |
| Supply Voltage Range | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Ensures compatibility with 5 V TTL/CMOS logic systems; matching ranges allow use in the same power rail design. |
| Number of Bits / Elements | 4 | 4 | Channel count must match to preserve signal routing and logic capacity in the target circuit. |
| Output Type | 3-State | 3-State | 3-state outputs allow bus sharing and high-impedance isolation; identical output type supports equivalent bus interfacing. |
| Logic Family | ACT | ACT | Same logic family ensures compatible input thresholds, drive strength, and speed characteristics. |
| Propagation Delay (Typical) | 8 ns | 8 ns | Timing performance affects maximum operating frequency and signal integrity; matching delays support equivalent timing budgets. |
| RoHS Status | RoHS Compliant | RoHS Compliant | Environmental compliance is required for many markets and affects procurement and disposal requirements. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74ACT125SCX | 74ACT125PC |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74ACT | 74ACT |
| Part Status | Obsolete | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 4 | 4 |
| Number of Bits per Element | 1 | 1 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 24mA, 24mA | 24mA, 24mA |
| Voltage - Supply | 4.5V ~ 5.5V | 4.5V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Through Hole |
Frequently asked questions
What are the main differences between the 74ACT125SCX and the 74ACT125PC?
The primary difference is the package type and mounting style. The 74ACT125SCX is supplied in a 14-lead SOIC package for surface-mount assembly, while the 74ACT125PC is supplied in a 14-lead PDIP package for through-hole mounting. Both are quad bus buffer gates with 3-state outputs from the 74ACT logic family.
Are the 74ACT125SCX and 74ACT125PC functionally equivalent?
Yes. Both devices are quad non-inverting bus buffers with 3-state outputs and active-low output enable pins. They share the same logic function and pinout, so the functional behavior in a circuit is the same when the package and mounting requirements are satisfied.
Can the 74ACT125SCX directly replace the 74ACT125PC on an existing PCB?
No, not without a board redesign. The 74ACT125SCX is a surface-mount SOIC device, while the 74ACT125PC is a through-hole PDIP device. The package footprints, lead pitch, and PCB land patterns differ, so a direct physical drop-in replacement is not possible.
Do the 74ACT125SCX and 74ACT125PC have the same operating voltage range?
Yes. Both devices are members of the 74ACT family and are specified for operation over the standard 4.5 V to 5.5 V supply voltage range, with 5 V nominal operation.
What is the difference in operating temperature range between the two parts?
Both the 74ACT125SCX and the 74ACT125PC are specified for the standard commercial temperature range of -40 °C to +85 °C, so there is no temperature-range difference between these two orderable part numbers.
Are the 74ACT125SCX and 74ACT125PC RoHS compliant?
RoHS status depends on the specific manufacturer and orderable part number. The 74ACT125SCX is typically offered as a RoHS-compliant surface-mount device, while the 74ACT125PC through-hole version may be available in both RoHS-compliant and non-compliant versions depending on the supplier. Verify the exact part number and manufacturer documentation before making a compliance decision.
Which part is better for new designs, the 74ACT125SCX or the 74ACT125PC?
For new designs, the 74ACT125SCX is generally preferred because surface-mount SOIC packages support automated assembly and higher PCB density. The 74ACT125PC remains useful for prototyping, legacy through-hole boards, and applications where a PDIP socket is required.
Do both parts provide the same output drive current?
Yes. Both the 74ACT125SCX and the 74ACT125PC are specified with ±24 mA output drive current at 5 V, consistent with the standard 74ACT125 electrical characteristics.