Part A
74HC541D
Toshiba Halbleiter und Speicher
- Lifecycle
- Active
- Stock
- 5041 Stückzahl
- Package
- SOIC-20
- Series
- Logic c Puffer, Treiber, Empfänger, Transceiver
Replacement verdict
Compatible functional replacement candidate
The 74HC540D and 74HC541D share the same HC-family CMOS process, 5 V supply range, SO-16 package, and pin count, making them functionally interchangeable in many designs. However, the 74HC540D provides inverting outputs while the 74HC541D provides non-inverting outputs, so the replacement is only valid when the logic polarity of the surrounding circuit is adjusted accordingly. Designers must confirm output polarity, input clamping behavior, and any downstream logic dependencies before substituting one for the other.
Output Type
High match
Package Type
High match
Supply Voltage
High match
Logic Polarity
Validation required
Parts at a glance
Part B
74HC540D
Toshiba Halbleiter und Speicher
- Lifecycle
- Active
- Stock
- 5312 Stückzahl
- Package
- SOIC-20
- Series
- Logic c Puffer, Treiber, Empfänger, Transceiver
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC540D | 74HC541D | Why it matters |
|---|---|---|---|
| Logic Function | Octal buffer/line driver with 3-state outputs, inverting | Octal buffer/line driver with 3-state outputs, non-inverting | The inversion determines the output polarity relative to the input, which directly affects signal logic and prevents direct functional substitution without accounting for polarity. |
| Output Type | 3-state, inverting | 3-state, non-inverting | 3-state outputs allow the device to be disconnected from the bus, but the inversion difference changes the logic level seen by downstream circuits. |
| Number of Channels | 8 | 8 | Both devices provide eight buffer channels, so the channel count is identical and does not affect substitutability. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | The supply voltage range must match the system voltage to ensure proper operation and logic level compatibility. |
| Output Drive Current | ±6 mA (at 4.5 V) | ±6 mA (at 4.5 V) | The output drive current determines the ability to drive loads and connected logic inputs without signal degradation. |
| Propagation Delay | Typically 8 ns (at 4.5 V) | Typically 8 ns (at 4.5 V) | Propagation delay affects timing margins in synchronous systems and must be compatible with the overall timing budget. |
| Package | SO16 | SO16 | Package compatibility ensures the device can be placed on the same PCB footprint without layout changes. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | The operating temperature range must cover the application environment to ensure reliable performance. |
| Pin Count | 16 | 16 | Pin count and pinout compatibility are essential for direct drop-in replacement on an existing PCB. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC541D | 74HC540D |
|---|---|---|
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Logic Type | Buffer, Non-Inverting | Buffer, Inverting |
| Number of Elements | 1 | 1 |
| Number of Bits per Element | 8 | 8 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 7.8mA, 7.8mA | 7.8mA, 7.8mA |
| 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 is the main functional difference between the 74HC540D and the 74HC541D?
The 74HC540D is an inverting octal buffer/line driver with 3-state outputs, while the 74HC541D is a non-inverting octal buffer/line driver with 3-state outputs. Both have the same pinout and drive capability, but the 74HC540D inverts the input signal at each output, whereas the 74HC541D passes the signal through without inversion.
Are the 74HC540D and 74HC541D pin-compatible?
Yes, both devices are offered in the same SO16 package (D suffix) and share an identical pinout: pins 1 and 19 are output enable inputs (active LOW), pins 2 through 9 are inputs, pins 10 and 20 are ground and VCC respectively, and pins 11 through 18 are outputs. This allows them to be used in the same PCB footprint.
Can the 74HC540D be replaced directly by the 74HC541D in an existing design?
Not without verifying the logic polarity required by the design. Because the 74HC540D inverts and the 74HC541D does not, a direct substitution will invert the signal state at every output, which may cause functional failure unless the system logic is adjusted accordingly.
What are the output drive capabilities of the 74HC540D and 74HC541D?
Both devices are specified with a standard output drive of ±6 mA at 5 V VCC (typical for 74HC series octal buffers). They are capable of driving bus lines and other moderate capacitive loads, but they are not intended for high-current drive applications.
What is the function of the two output enable pins on the 74HC540D and 74HC541D?
Both devices have two active-LOW output enable inputs (pins 1 and 19). When either enable pin is HIGH, the corresponding outputs are placed in a high-impedance (3-state) condition. When both enable pins are LOW, the outputs are active and reflect the input logic (inverted for the 74HC540D, non-inverted for the 74HC541D).
Do the 74HC540D and 74HC541D have the same propagation delay and switching characteristics?
Yes, because both devices are built on the same 74HC CMOS process and have identical internal buffer stages except for the output inversion stage. Their propagation delay, output transition times, and maximum operating frequency are essentially identical and are specified in the respective manufacturer datasheets under the same conditions.
What are the recommended operating voltage and temperature ranges for the 74HC540D and 74HC541D?
Both devices operate over a supply voltage range of 2 V to 6 V and an ambient temperature range of -40 °C to +125 °C, as specified in standard 74HC series datasheets from manufacturers such as Nexperia, Texas Instruments, and ON Semiconductor.
Are the 74HC540D and 74HC541D available in the same package options?
Yes, both are commonly available in the SO16 (D) package, as indicated by the "D" suffix in the part numbers. They may also be offered in other packages such as TSSOP or DIP by various manufacturers, but the SO16 package is the standard surface-mount option for both devices.