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
Compatible functional replacement candidate
The 74LCX244MTC and 74LCX541TTR are both low-voltage CMOS octal buffers from the LCX family, sharing identical logic function, supply voltage range, and drive characteristics. However, they differ in package footprint and pinout, and the 74LCX541TTR provides a flow-through architecture with dual enable inputs, making it a functional candidate rather than a direct drop-in replacement. Designers must verify PCB layout and enable-pin routing before substitution.
Logic Function
High match
Supply Voltage Range
High match
Package Type
Validation required
Pin Configuration
Validation required
Parts at a glance
Part B
74LCX541TTR
RFE/フューゼテック
- Lifecycle
- Active
- Stock
- 4250 個数
- Package
- TSSOP-20
- 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 | 74LCX541TTR | Why it matters |
|---|---|---|---|
| Logic Family | LCX | LCX | Same logic family ensures compatible voltage levels and switching characteristics for direct substitution. |
| Function | Octal Buffer/Line Driver, 3-State | Octal Buffer/Line Driver, 3-State | Both provide the same buffering function, making them functionally interchangeable in most designs. |
| Output Enable Polarity | Active-Low (dual OE pins) | Active-Low (dual OE pins) | Enable polarity must match the control logic to ensure correct tri-state operation. |
| Number of Channels | 8 | 8 | Channel count determines how many signal lines can be buffered simultaneously. |
| Supply Voltage Range | 2.0 V to 3.6 V | 2.0 V to 3.6 V | Compatible supply range ensures the device operates correctly in the target system voltage. |
| Output Drive Current | ±24 mA | ±24 mA | Drive strength must meet the load requirements of the connected circuitry. |
| Propagation Delay | 6.5 ns (max at 3.3 V) | 6.5 ns (max at 3.3 V) | Propagation delay affects timing margins in high-speed signal paths. |
| Package Type | TSSOP-20 | TSSOP-20 | Package must match the PCB footprint for physical compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range must cover the application environment for reliable operation. |
| Input Type | Standard CMOS | Standard CMOS | Input type affects compatibility with upstream logic and noise immunity. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LCX244MTC | 74LCX541TTR |
|---|---|---|
| Supplier | - | STMicroelectronics |
| Series | 74LCX | 74LCX |
| Part Status | Active | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 2 | 1 |
| Number of Bits per Element | 4 | 8 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | - | 24mA, 24mA |
| Voltage - Supply | 2V ~ 3.6V | 2V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C (TA) | -55°C ~ 125°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 74LCX541TTR?
The 74LCX244MTC is an octal buffer/line driver with 3-state outputs, featuring two active-low output enable pins (1OE and 2OE) that independently control four outputs each. The 74LCX541TTR is also an octal buffer/line driver with 3-state outputs, but it features two active-low output enable pins (1OE and 2OE) that control all eight outputs simultaneously in a single group. Both devices provide non-inverting signal paths.
Are the 74LCX244MTC and 74LCX541TTR pin-to-pin compatible?
No. The 74LCX244MTC is supplied in a 20-pin TSSOP package (MTC suffix), while the 74LCX541TTR is supplied in a 20-pin TSSOP package (TTR suffix). Although both use a 20-pin TSSOP footprint, the pinout assignments differ. The 74LCX244MTC has its output enable pins on pins 1 and 19, whereas the 74LCX541TTR has its output enable pins on pins 1 and 19 as well, but the input/output pin ordering differs between the two devices. Designers must verify the specific pinout from the respective manufacturer datasheets before considering a layout change.
Can the 74LCX244MTC and 74LCX541TTR be used interchangeably in an existing design?
Not without design verification. While both are octal non-inverting 3-state buffers operating over the same 2.0 V to 3.6 V VCC range and offering similar propagation delays and drive currents, the differences in output enable grouping and pinout mean that a direct drop-in replacement is not guaranteed. The 74LCX244MTC allows independent control of two 4-bit groups, whereas the 74LCX541TTR controls all eight outputs as a single group. Circuit functionality and PCB layout must be validated against the target device's datasheet.
What are the operating voltage and logic level specifications for these devices?
Both the 74LCX244MTC and 74LCX541TTR are LCX-family CMOS devices designed for 2.0 V to 3.6 V VCC operation. They are 5 V tolerant on inputs and outputs when VCC is within the specified range, allowing interfacing with 5 V logic systems. Both devices feature typical propagation delay (tPD) of approximately 6.5 ns at 3.3 V and can sink/source ±24 mA at 3.0 V VCC, making them suitable for bus-interface and memory-driver applications.
What are the package and thermal characteristics of the 74LCX244MTC and 74LCX541TTR?
The 74LCX244MTC is offered in a 20-pin TSSOP package (MTC suffix) with an operating temperature range of -40°C to +85°C. The 74LCX541TTR is also offered in a 20-pin TSSOP package (TTR suffix) with the same operating temperature range. Both packages are surface-mount and comply with standard TSSOP land patterns. Thermal resistance and power dissipation ratings should be confirmed from the specific manufacturer datasheet, as they may vary slightly between suppliers.
Which device is better for applications requiring independent control of output groups?
The 74LCX244MTC is better suited for applications requiring independent control of two separate 4-bit output groups, because its two active-low output enable pins each control four outputs. The 74LCX541TTR controls all eight outputs with its enable pins, so it is more appropriate for applications where the entire octal buffer must be enabled or disabled as a single unit. The choice depends on the system's need for grouped versus global output enable control.
Do both devices support live insertion and power-down protection?
Yes. Both the 74LCX244MTC and 74LCX541TTR are designed with power-down protection on inputs and outputs, which prevents damaging current backflow when the device is powered down (VCC = 0 V). This feature supports live insertion and removal in bus-oriented systems. Additionally, both devices include 5 V tolerant inputs and outputs, allowing them to interface with higher-voltage logic without additional level shifters.