Part A
74AC244SCX
Fairchild Semiconductor Inc
- Lifecycle
- Active
- Stock
- 2840 PCS
- Package
- SOIC-W-20
- Series
- Logique - Buffers, lecteurs, récepteurs, émetteurs - récepteurs
Replacement verdict
Not a drop-in replacement
The 74AC244SCX and 74AC241SJX are not functionally interchangeable despite sharing the same AC-family logic and 20-pin package footprint. The 74AC244SCX is a dual 4-bit non-inverting buffer/line driver with active-low output enables, while the 74AC241SJX is an octal buffer/line driver featuring a split enable architecture with one active-low and one active-high enable, and it provides inverting outputs on one half of the device. These differences in output polarity, enable logic, and channel configuration prevent direct substitution without circuit redesign.
Different output polarity
Different enable logic
Different channel configuration
Different package footprint
Parts at a glance
Part B
74AC241SJX
Semi - conducteurs
- Lifecycle
- Active
- Stock
- 5557 PCS
- Package
- SOIC-20
- Series
- Logique - Buffers, lecteurs, récepteurs, émetteurs - récepteurs
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74AC244SCX | 74AC241SJX | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver, non-inverting, with 3-state outputs | Octal Buffer/Line Driver, inverting, with 3-state outputs | The 244 provides non-inverting outputs while the 241 provides inverting outputs, so they are not functionally interchangeable in a signal path without accounting for polarity. |
| Output Polarity | Non-inverting | Inverting | Polarity determines whether the output logic level matches or is inverted relative to the input, directly affecting circuit behavior. |
| Enable Control Configuration | Two active-low output enables (1OE, 2OE) | One active-low and one active-high output enable (1OE, 2OE) | Different enable polarities change how the device is controlled and how it interfaces with surrounding logic, affecting direct substitution. |
| Package / Mounting | SOIC-20 (surface mount) | SOIC-20 (surface mount) | Package and mounting type must match for physical board compatibility; both share SOIC-20 but are distinct orderable part numbers. |
| Number of Channels | 8 | 8 | Channel count must match for equivalent bus width handling; both provide eight buffers. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Operating voltage range must be compatible with the system supply; both support the AC family range. |
| Output Drive Current | ±24 mA | ±24 mA | Drive current determines fan-out and ability to drive loads; matching values support similar loading conditions. |
| Propagation Delay | Typical ~5 ns at 5 V | Typical ~5 ns at 5 V | Propagation delay affects timing margins; similar delays help maintain system timing when substituting. |
| Logic Family | AC (Advanced CMOS) | AC (Advanced CMOS) | Same logic family ensures compatible input thresholds, noise margins, and speed characteristics. |
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 | 74AC244SCX | 74AC241SJX |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74AC | 74AC |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 2 | 2 |
| Number of Bits per Element | 4 | 4 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 24mA, 24mA | 24mA, 24mA |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the main functional differences between the 74AC244SCX and the 74AC241SJX?
The 74AC244SCX is an octal buffer/line driver with 3-state outputs, featuring two active-low output enable pins (1OE and 2OE) that control four outputs each. The 74AC241SJX is also an octal buffer/line driver with 3-state outputs, but it features two active-low output enable pins (1OE and 2OE) that control four outputs each, with the key difference being that the 74AC241 has non-inverting outputs for one group and inverting outputs for the other group, whereas the 74AC244 has all non-inverting outputs.
Are the 74AC244SCX and 74AC241SJX pin-to-pin compatible?
No. The 74AC244SCX and 74AC241SJX have different pinout configurations. The 74AC244SCX has all non-inverting outputs, while the 74AC241SJX has a mix of inverting and non-inverting outputs, resulting in different signal polarity on specific pins. Therefore, they are not direct pin-to-pin replacements without accounting for the output polarity differences.
What are the package types for the 74AC244SCX and 74AC241SJX?
The 74AC244SCX is supplied in a 20-pin SOIC (Small Outline Integrated Circuit) package, with the "SCX" suffix indicating tape and reel packaging. The 74AC241SJX is supplied in a 20-pin SOP (Small Outline Package) with the "SJX" suffix indicating tape and reel packaging. Both are surface-mount packages, but the specific package codes (SC vs SJ) may correspond to different body widths or lead pitches as defined by the manufacturer.
Can the 74AC244SCX and 74AC241SJX operate at the same supply voltage and temperature ranges?
Yes. Both devices are members of the AC family and typically operate over a supply voltage range of 2.0 V to 6.0 V, with a standard operating temperature range of -40 °C to +85 °C for industrial-grade versions. However, always verify the exact specifications from the manufacturer datasheet for the specific part number and suffix.
What is the output drive capability of the 74AC244SCX and 74AC241SJX?
Both the 74AC244SCX and 74AC241SJX typically provide ±24 mA output drive at 5.0 V VCC, which is standard for AC-family octal buffers. This allows them to drive moderate capacitive loads and resistive terminations in bus-oriented applications. Confirm the exact IOH/IOL ratings from the manufacturer datasheet for the specific device.
Which device is better for inverting a signal, the 74AC244SCX or the 74AC241SJX?
The 74AC241SJX is the appropriate choice when signal inversion is required, as it provides inverting outputs on one of its two 4-bit groups. The 74AC244SCX provides only non-inverting outputs and cannot invert signals. If both non-inverting and inverting outputs are needed in the same design, the 74AC241SJX offers that flexibility in a single package.
Are the 74AC244SCX and 74AC241SJX interchangeable in a 3-state bus application?
They are not directly interchangeable without design changes. While both feature 3-state outputs and similar enable logic, the 74AC241SJX has inverting outputs on half of its channels, which would invert the bus data on those lines. The 74AC244SCX maintains non-inverted data on all channels. Substitution requires verifying output polarity, pinout, and timing compatibility with the target design.
What are the typical propagation delays for the 74AC244SCX and 74AC241SJX?
Both devices typically exhibit propagation delays in the range of 3 ns to 8 ns at 5.0 V VCC and 25 °C, depending on the load conditions and the specific manufacturer. The 74AC241SJX may have slightly different tPHL and tPLH values for its inverting versus non-inverting outputs. Always consult the manufacturer datasheet for guaranteed maximum delays over the full operating temperature range.