Part A
74VHC541FT
東芝電晶體與存儲
- Lifecycle
- Active
- Stock
- 5516 件
- Package
- TSSOP-20
- Series
- 邏輯-緩衝器、驅動器、接收器、收發器
Replacement verdict
Compatible functional replacement candidate
The 74VHC541FT and 74VHC244SJX are both octal non-inverting buffers from the VHC family, sharing identical logic function, supply voltage range, and drive strength. The primary distinction lies in their pinout and package configuration, which requires careful validation before substitution in existing designs.
Logic Function
High match
Supply Voltage Range
High match
Package Type
Validation required
Pin Configuration
Validation required
Parts at a glance
Part B
74VHC244SJX
安森美
- Lifecycle
- Active
- Stock
- 6432 件
- Package
- SOIC-20
- Series
- 邏輯-緩衝器、驅動器、接收器、收發器
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74VHC541FT | 74VHC244SJX | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-state outputs (non-inverting) | Octal Buffer/Line Driver with 3-state outputs (non-inverting) | Both are non-inverting octal buffers, so the basic signal path function is equivalent. |
| Enable Control | Two active-low output enable pins (OE1, OE2) | Two active-low output enable pins (OE1, OE2) | Enable polarity and count affect how the device is gated in a circuit; identical here. |
| Pin Count / Package | 20-pin TSSOP (FT suffix) | 20-pin SOIC (SJX suffix) | Package footprint and thermal/assembly characteristics differ, affecting PCB layout and drop-in compatibility. |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | Both support the same VHC operating range, allowing use in 2.5 V, 3.3 V, and 5 V systems. |
| Output Drive Current | ±8 mA at 5 V | ±8 mA at 5 V | Drive strength determines fan-out and ability to drive capacitive or low-impedance loads. |
| Propagation Delay | ~5.5 ns at 5 V (typical) | ~5.5 ns at 5 V (typical) | Timing performance affects maximum operating frequency and signal integrity in synchronous designs. |
| Input Type | CMOS/TTL-compatible | CMOS/TTL-compatible | Input compatibility ensures the device can interface with both CMOS and TTL logic levels. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range supports use in harsh environments and automotive/industrial applications. |
| Pinout Configuration | Inputs on one side, outputs on opposite side (flow-through) | Inputs and outputs interleaved (non-flow-through) | Pinout differences affect PCB routing and whether the parts are drop-in replacements. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC541FT | 74VHC244SJX |
|---|---|---|
| Supplier | - | onsemi,Rochester Electronics, LLC |
| Series | 74VHC | 74VHC |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 1 | 2 |
| Number of Bits per Element | 8 | 4 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the 74VHC541FT and the 74VHC244SJX?
The 74VHC541FT is an octal buffer/line driver with 3-state outputs and a dual enable structure (active-low OE1 and OE2), providing non-inverting signal buffering. The 74VHC244SJX is an octal buffer/line driver with 3-state outputs organized as two 4-bit sections, each with its own active-low output enable (1OE and 2OE), also non-inverting. Both are VHC-family CMOS devices, but the 541 offers a single 8-bit enable path while the 244 provides two independent 4-bit enable paths.
Are the 74VHC541FT and 74VHC244SJX pin-to-pin compatible?
No. The 74VHC541FT is typically supplied in a TSSOP-20 package, while the 74VHC244SJX is supplied in an SOIC-20 package. Although both use a 20-pin count, the package footprints and land patterns differ, so they are not drop-in replacements without PCB redesign. Pin functions also differ: the 541 uses OE1 and OE2 on pins 1 and 19, whereas the 244 uses 1OE and 2OE on pins 1 and 19 with a different internal channel grouping.
Can the 74VHC541FT and 74VHC244SJX operate at the same supply voltage range?
Yes. Both devices are members of the VHC logic family and are specified for a supply voltage range of 2.0 V to 5.5 V, with typical operation at 3.3 V or 5.0 V. This makes them compatible with mixed-voltage systems within that range, subject to the recommended operating conditions in the respective manufacturer datasheets.
Do both devices provide 3-state outputs for bus-oriented applications?
Yes. Both the 74VHC541FT and 74VHC244SJX feature 3-state outputs that can be placed in a high-impedance state via their active-low output enable pins. This allows them to be used in bus-sharing and multiplexed signal routing applications where multiple drivers share a common line.
How do the output drive capabilities of the 74VHC541FT and 74VHC244SJX compare?
Both devices are specified with symmetrical output drive of ±8 mA at 5.0 V VCC, which is typical for VHC-family octal buffers. This drive strength supports direct interfacing with standard CMOS and TTL-compatible inputs. For precise limits, refer to the DC electrical characteristics in the respective manufacturer datasheets.
Which device is better suited for applications requiring independent control of two 4-bit signal groups?
The 74VHC244SJX is better suited because it provides two independent active-low output enable pins (1OE and 2OE), each controlling a 4-bit section. This allows one half of the device to be active while the other half is in high-impedance mode. The 74VHC541FT uses two enable pins that control the full 8-bit output, so it does not offer the same split-section control granularity.
Are the 74VHC541FT and 74VHC244SJX interchangeable in existing designs?
No, they are not directly interchangeable. Differences in package type (TSSOP-20 vs SOIC-20), pin function assignments, and output enable architecture mean that a direct substitution would require PCB layout changes and verification of enable logic behavior. Designers must validate timing, loading, and control signal mapping against the target design before considering a replacement.
What are the typical propagation delay specifications for these devices?
Both the 74VHC541FT and 74VHC244SJX typically exhibit propagation delays in the range of approximately 3.5 ns to 5.5 ns at 5.0 V VCC and 25°C, depending on the specific manufacturer and load conditions. These values are consistent with VHC-family high-speed CMOS logic. Exact limits should be confirmed from the respective datasheets.