Part A
74VHC244FT
東芝電晶體與存儲
- Lifecycle
- Active
- Stock
- 2156 件
- Package
- TSSOP-20
- Series
- 邏輯-緩衝器、驅動器、接收器、收發器
Replacement verdict
Not a drop-in replacement
The 74VHC244FT and 74VHC04FT are not functionally interchangeable. The 74VHC244FT is a quad non-inverting buffer with 3-state outputs, while the 74VHC04FT is a hex inverting gate. Their logic functions, channel counts, output drive configurations, and pin assignments differ fundamentally, making direct substitution impossible without circuit redesign.
Different logic function
Different channel count
Different output type
Different pinout
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74VHC244FT | 74VHC04FT | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-State Outputs | Hex Inverter | Defines the fundamental signal-processing behavior; a buffer passes signals with drive capability while an inverter complements the logic level, so they are not functionally interchangeable. |
| Number of Channels | 8 | 6 | Channel count determines how many independent signal lines can be handled by a single package, affecting board layout and component count. |
| Output Type | 3-State | Push-Pull | 3-state outputs allow the device to be disconnected from a bus for multiplexing, whereas push-pull outputs always drive the line high or low. |
| Logic Level Type | Non-Inverting | Inverting | Determines whether the output polarity matches the input; substituting one for the other would invert the signal and break circuit functionality. |
| Control Input | Output Enable (active LOW) | None | The presence of an enable pin allows bus sharing and power-saving tri-state control, which the inverter lacks. |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | Both parts operate over the same VHC supply window, so they are compatible with the same logic-level power rails. |
| Propagation Delay (typical at 5 V) | 3.8 ns | 4.3 ns | Similar propagation delays mean comparable timing performance in high-speed digital paths. |
| Output Drive Current | ±8 mA | ±8 mA | Matching drive strength ensures both devices can sink and source similar loads without additional buffering. |
| Package | TSSOP-20 | TSSOP-14 | Different pin counts and footprints mean the two parts are not drop-in replacements on an existing PCB. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings make both suitable for the same industrial and commercial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC244FT | 74VHC04FT |
|---|---|---|
| Supplier | - | Toshiba Semiconductor and Storage |
| Series | 74VHC | 74VHC |
| Part Status | Active | Active |
| Logic Type | Buffer, Non-Inverting | Inverter |
| Number of Circuits | - | 6 |
| Number of Inputs | - | 1 |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Current - Quiescent (Max) | - | 2 µA |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Max Propagation Delay @ V Max CL | - | 7.5ns @ 5V, 50pF |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Elements | 2 | - |
| Number of Bits per Element | 4 | - |
| Output Type | 3-State | - |
Frequently asked questions
What are the primary functional differences between the 74VHC244FT and the 74VHC04FT?
The 74VHC244FT is an octal non-inverting buffer/line driver with 3-state outputs, while the 74VHC04FT is a hex inverter with standard push-pull outputs. The 74VHC244FT provides eight buffer channels with tri-state control for bus-oriented applications, whereas the 74VHC04FT provides six independent inverter channels for signal inversion.
Are the 74VHC244FT and 74VHC04FT pin-compatible?
No. The 74VHC244FT and 74VHC04FT have different pin counts and pinouts. The 74VHC244FT is typically offered in a 20-pin package (e.g., TSSOP-20), while the 74VHC04FT is typically offered in a 14-pin package (e.g., TSSOP-14). They cannot be used as drop-in replacements for each other.
Can the 74VHC244FT and 74VHC04FT operate from the same supply voltage range?
Yes. Both devices are members of the VHC (Very High Speed CMOS) 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 common low-voltage logic systems.
Does the 74VHC244FT have 3-state outputs while the 74VHC04FT does not?
Yes. The 74VHC244FT features 3-state outputs controlled by two active-low output enable pins (1OE and 2OE), allowing its outputs to be placed in a high-impedance state for bus sharing. The 74VHC04FT has standard push-pull outputs and does not support a high-impedance state.
What are the typical propagation delay characteristics of these two devices?
Both devices are VHC-family CMOS logic and offer similar high-speed performance. At a 5.0 V supply, the 74VHC244FT typically exhibits a propagation delay (tPD) of approximately 3.5 ns to 5.0 ns, while the 74VHC04FT typically exhibits a tPD of approximately 3.0 ns to 4.5 ns. Exact values depend on load conditions and are specified in the respective manufacturer datasheets.
Are the 74VHC244FT and 74VHC04FT interchangeable in a design?
No. They are not functionally interchangeable. The 74VHC244FT is a non-inverting octal buffer with 3-state outputs, while the 74VHC04FT is a hex inverter. Substitution would require redesigning the circuit to account for differences in logic function, channel count, pinout, and output type.
What are the typical output drive capabilities of the 74VHC244FT and 74VHC04FT?
Both devices typically provide symmetrical output drive of ±8 mA at 5.0 V, which is standard for the VHC logic family. This drive strength is suitable for driving moderate capacitive loads and standard CMOS inputs.
Which device is more suitable for bus driving applications?
The 74VHC244FT is more suitable for bus driving applications because it features 3-state outputs that allow multiple devices to share a common bus without contention. The 74VHC04FT, with its push-pull outputs, is intended for point-to-point signal inversion and is not designed for bus sharing.