Part A
74LCX244MTC
オンセミコンダクター社
- Lifecycle
- Active
- Stock
- 5042 個数
- Series
- ロジック - バッファ、ドライバ、レシーバ、トランシーバ
Replacement verdict
Not a drop-in replacement
The 74LCX244MTC and 74LCX07YTTR are not functionally interchangeable. The 74LCX244MTC is a non-inverting octal buffer with 3-state outputs, while the 74LCX07YTTR is a hex buffer with open-drain outputs. They differ in channel count, output type, package, and pull-up requirements, so direct substitution is not possible without circuit redesign.
Different output type
Different channel count
Different package
External pull-up may be required
Parts at a glance
Part B
74LCX07YTTR
RFE/フューゼテック
- Lifecycle
- Active
- Stock
- 57 個数
- Package
- TSSOP-14
- Series
- ロジック - バッファ、ドライバ、レシーバ、トランシーバ
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74LCX244MTC | 74LCX07YTTR | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver with 3-State Outputs | Hex Buffer with Open-Drain Outputs | Determines the fundamental signal-routing behavior; a 3-state driver and an open-drain buffer are not functionally interchangeable in most circuits. |
| Number of Channels | 8 | 6 | Channel count affects how many signal lines can be buffered by a single package, impacting board layout and component count. |
| Output Type | 3-State | Open-Drain | 3-state outputs can drive both high and low, while open-drain outputs only pull low and require external pull-up resistors, changing the interface design. |
| Direction Control | Unidirectional with Output Enable (OE) | Unidirectional (no enable) | The presence of an output-enable pin allows bus sharing and high-impedance states, which the open-drain buffer cannot provide. |
| Supply Voltage Range | 2.0 V to 3.6 V | 1.65 V to 5.5 V | The wider supply range of the 74LCX07YTTR allows operation in lower-voltage and mixed-voltage systems where the 74LCX244MTC cannot be used. |
| Maximum Operating Frequency | Not specified as a single parameter (propagation delay ~6.5 ns at 3.3 V) | Not specified as a single parameter (propagation delay ~5.5 ns at 3.3 V) | Propagation delay influences maximum usable clock or signal rate; the two parts have different timing characteristics that affect high-speed designs. |
| Output Drive Current (Low) | 24 mA | 32 mA | Sink current capability determines how many loads or how much capacitance can be driven low, affecting fan-out and signal integrity. |
| Output Drive Current (High) | 24 mA | 0 mA (open-drain, requires pull-up) | The 74LCX244MTC can actively drive high, while the 74LCX07YTTR cannot source current, requiring external pull-up resistors and limiting high-level drive strength. |
| Package | 20-TSSOP | 14-TSSOP | Different pin counts and package sizes affect PCB footprint, routing, and mechanical compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +125 °C | The wider temperature range of the 74LCX07YTTR makes it suitable for harsher environments such as automotive or industrial applications. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX244MTC | 74LCX07YTTR |
|---|---|---|
| Supplier | - | STMicroelectronics |
| Series | 74LCX | Automotive, AEC-Q100, 74LCX |
| Part Status | Active | Active |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 2 | 6 |
| Number of Bits per Element | 4 | 1 |
| Output Type | 3-State | Open Drain |
| Current - Output High Low | - | -, 24mA |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | 74LCX244 | - |
| Current - Output High, Low | 24mA, 24mA | - |
| Packaging | Tube | - |
Frequently asked questions
What are the primary functional differences between the 74LCX244MTC and the 74LCX07YTTR?
The 74LCX244MTC is an octal buffer/line driver with 3-state outputs, designed for bus-oriented applications. The 74LCX07YTTR is a hex buffer/driver with open-drain outputs, intended for wired-OR or wired-AND logic and level-shifting applications. The 74LCX244MTC has 8 channels with 3-state control, while the 74LCX07YTTR has 6 channels with open-drain outputs and no 3-state control.
Are the 74LCX244MTC and 74LCX07YTTR pin-to-pin compatible?
No. The 74LCX244MTC is supplied in a 20-pin TSSOP package, while the 74LCX07YTTR is supplied in a 14-pin TSSOP package. They have different pin counts and pinouts, so they are not pin-to-pin compatible.
Can the 74LCX244MTC and 74LCX07YTTR operate at the same supply voltage?
Yes. Both devices are part of the LCX family and are specified for a supply voltage range of 2.0 V to 3.6 V, with typical operation at 3.3 V. However, the 74LCX07YTTR open-drain outputs may require external pull-up resistors to a voltage that can differ from the device supply, depending on the application.
What is the difference in output drive capability between the 74LCX244MTC and the 74LCX07YTTR?
The 74LCX244MTC provides standard push-pull outputs with specified DC output drive of ±24 mA at 3.0 V. The 74LCX07YTTR provides open-drain outputs with a specified sink current of 24 mA at 3.0 V, but it does not source current; the high state is achieved via an external pull-up resistor.
Which device is better suited for bidirectional bus applications?
The 74LCX244MTC is better suited for bidirectional bus applications because it features 3-state outputs that allow the bus to be isolated when the output enable (OE) pins are deasserted. The 74LCX07YTTR has open-drain outputs without 3-state control, making it less suitable for bidirectional bus multiplexing.
Do both devices support 5 V tolerant inputs?
Yes. Both the 74LCX244MTC and the 74LCX07YTTR are specified with 5 V tolerant inputs, allowing them to interface with 5 V logic systems while operating from a 3.3 V supply. This is a common feature of the LCX logic family.
What are the typical propagation delay specifications for these two devices?
The 74LCX244MTC has a typical propagation delay (tPD) of approximately 6.5 ns at 3.3 V. The 74LCX07YTTR has a typical propagation delay of approximately 5.5 ns at 3.3 V. Actual values depend on load conditions and supply voltage, and designers should consult the respective manufacturer datasheets for guaranteed limits.
Are the 74LCX244MTC and 74LCX07YTTR available in the same package type?
No. The 74LCX244MTC is offered in a 20-pin TSSOP package (MTC suffix). The 74LCX07YTTR is offered in a 14-pin TSSOP package (YTTR suffix). The package types are similar (TSSOP), but the pin counts and body sizes differ.