Part A
74VHC244FT
도시바 반도체 및 스토리지
- Lifecycle
- Active
- Stock
- 2156 PCS
- Package
- TSSOP-20
- Series
- 논리 - 버퍼, 드라이브, 수신기, 트랜시버
Replacement verdict
Not a drop-in replacement
The 74VHC244FT and 74VHC00TTR are not functionally interchangeable. The 74VHC244FT is an octal non-inverting buffer/line driver with 3-state outputs, while the 74VHC00TTR is a quad 2-input NAND gate. Their logic functions, channel configurations, pinouts, and output structures are fundamentally different, making direct substitution impossible without circuit redesign.
Different logic function
Different channel count
Different output type
Different pinout
Parts at a glance
Part B
74VHC00TTR
ST마이크로일렉트로닉스(주)
- Lifecycle
- Active
- Stock
- 5852 PCS
- Series
- 로직 - 도어 및 인버터
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 | 74VHC00TTR | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-State Outputs | Quad 2-Input NAND Gate | The core logic function determines whether the devices are functionally interchangeable; a buffer/driver and a NAND gate perform entirely different operations. |
| Number of Gates/Channels | 8 buffers (2 groups of 4) | 4 NAND gates | Channel count affects how many signals can be processed simultaneously in a design. |
| Output Type | 3-State | Push-Pull (totem-pole) | 3-state outputs allow bus sharing and high-impedance isolation, while push-pull outputs cannot be tied together without contention. |
| Number of Inputs per Element | 1 (per buffer) | 2 (per gate) | Input count per element defines the logic capability and pin utilization of each device. |
| Control Inputs | 2 Output Enable (OE) pins | None | Enable pins allow dynamic control of output state, which is essential for bus arbitration and power management. |
| Propagation Delay (tpd) | ~5.5 ns (typical at 5V) | ~5.0 ns (typical at 5V) | Propagation delay impacts maximum operating frequency and timing margins in synchronous systems. |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | Both support the same VHC voltage range, enabling compatibility with 3.3V and 5V logic systems. |
| Output Drive Current (IOH/IOL) | ±8 mA | ±8 mA | Drive current determines fan-out capability and ability to drive transmission lines or LEDs. |
| Package Type | TSSOP-20 | TSSOP-14 | Package footprint and pin count must match the PCB layout for physical substitutability. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range ensures reliable operation in industrial and automotive environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC244FT | 74VHC00TTR |
|---|---|---|
| Supplier | - | STMicroelectronics |
| Series | 74VHC | 74VHC |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | NAND Gate |
| Number of Circuits | - | 4 |
| Number of Inputs | - | 2 |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Current - Quiescent (Max) | - | 2 µA |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Logic Level - Low | - | 0.5V |
| Logic Level - High | - | 1.5V |
| Max Propagation Delay @ V Max CL | - | 7.5ns @ 5V, 50pF |
| Operating Temperature | -40°C ~ 125°C (TA) | -55°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 74VHC00TTR?
The 74VHC244FT is an octal non-inverting buffer/line driver with 3-state outputs, while the 74VHC00TTR is a quad 2-input NAND gate. They serve different logic functions and are not functionally interchangeable.
Do the 74VHC244FT and 74VHC00TTR share the same package type?
No. The 74VHC244FT is typically supplied in a TSSOP-20 package, whereas the 74VHC00TTR is supplied in a TSSOP-14 package. The different pin counts and footprints prevent direct PCB substitution.
Are the 74VHC244FT and 74VHC00TTR compatible with the same supply voltage range?
Yes. Both devices are members of the 74VHC logic family and operate over a recommended supply voltage range of 2.0 V to 5.5 V, with typical operation at 3.3 V or 5.0 V.
Can the 74VHC244FT be used to replace the 74VHC00TTR in a logic circuit?
No. The 74VHC244FT is a buffer/driver with 3-state outputs, while the 74VHC00TTR performs a specific NAND logic function. Replacing one with the other would alter the circuit's logic behavior and is not a valid substitution.
What are the output drive capabilities of the 74VHC244FT compared to the 74VHC00TTR?
Both devices typically provide symmetrical output drive of ±8 mA at 5.0 V VCC, as specified in the 74VHC family datasheets. However, the 74VHC244FT includes 3-state control, which the 74VHC00TTR does not.
Do both the 74VHC244FT and 74VHC00TTR support 3-state output operation?
No. Only the 74VHC244FT features 3-state outputs controlled by two active-low output enable pins. The 74VHC00TTR has standard push-pull outputs without a high-impedance state.
Are the 74VHC244FT and 74VHC00TTR available in the same operating temperature range?
Yes. Both devices are typically specified for the industrial temperature range of -40 °C to +85 °C, as listed in their respective manufacturer datasheets.