Part A
74LVTH244MTC
onsemi
- Lifecycle
- Active
- Stock
- 1272 PCS
- Package
- TSSOP-20
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Not a drop-in replacement
The 74LVTH244MTC and 74LVT240MTCX are not functionally interchangeable. Although both are 3.3 V octal buffers in the same TSSOP-20 package, they differ in logic function, output polarity, and bus-hold capability, requiring a full design review before any substitution.
Different logic function
Different output polarity
Different bus-hold feature
Different input structure
Parts at a glance
Part B
74LVT240MTCX
onsemi
- Lifecycle
- Active
- Stock
- 5059 PCS
- Package
- TSSOP-20
- Series
- Logic - Buffers, Drivers, Receivers, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74LVTH244MTC | 74LVT240MTCX | Why it matters |
|---|---|---|---|
| Logic Function | Octal Buffer/Line Driver (non-inverting), 3-state | Octal Buffer/Line Driver (inverting), 3-state | Determines output polarity; a non-inverting buffer cannot directly replace an inverting buffer without logic inversion elsewhere in the design. |
| Output Polarity | Non-inverting (Y = A) | Inverting (Y = A̅) | Signal polarity must match the surrounding circuit; mismatched polarity causes functional failure. |
| Enable Control | Active-low output enable (OE̅) on both banks | Active-low output enable (OE̅) on both banks | Both use active-low enables, so the control interface is compatible, but the inverted data path still differs. |
| Bus-Hold Feature | Yes (H suffix indicates bus-hold) | No | Bus-hold keeps unused inputs at a defined level, preventing floating-input oscillation; its absence requires external pull-up/pull-down resistors. |
| Supply Voltage Range | 2.7 V to 3.6 V | 2.7 V to 3.6 V | Both operate over the same low-voltage range, so power-supply compatibility is maintained. |
| Output Drive Current | ±32 mA (at 3.0 V) | ±32 mA (at 3.0 V) | Identical drive strength means either device can drive the same load without re-evaluating fan-out. |
| Propagation Delay | ~3.5 ns (typical, 3.3 V) | ~3.5 ns (typical, 3.3 V) | Similar timing performance supports drop-in use in most timing-sensitive paths. |
| Package | TSSOP-20 | TSSOP-20 | Same footprint and pin count allow direct PCB replacement without layout changes. |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings ensure both parts suit the same industrial/commercial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74LVTH244MTC | 74LVT240MTCX |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74LVTH | 74LVT |
| Part Status | Obsolete | Obsolete |
| Logic Type | Buffer, Non-Inverting | Buffer, Inverting |
| Number of Elements | 2 | 2 |
| Number of Bits per Element | 4 | 4 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 32mA, 64mA | 32mA, 64mA |
| Voltage - Supply | 2.7V ~ 3.6V | 2.7V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the main functional differences between the 74LVTH244MTC and the 74LVT240MTCX?
The 74LVTH244MTC is an octal buffer/line driver with 3-state outputs and non-inverting data paths. The 74LVT240MTCX is an octal buffer/line driver with 3-state outputs and inverting data paths. Both are 20-pin devices in TSSOP packages, but the '244 provides non-inverted outputs while the '240 provides inverted outputs.
Are the 74LVTH244MTC and 74LVT240MTCX pin-to-pin compatible?
No. Although both are 20-pin TSSOP devices, the pinout differs because the '244 has non-inverting outputs and the '240 has inverting outputs. The input and output assignments are not identical, so they cannot be used as direct drop-in replacements without verifying the pin functions against the respective datasheets.
What is the difference between the LVTH and LVT logic families?
The LVTH family includes bus-hold circuitry on the inputs, which keeps unused or floating inputs at a defined logic level without external pull-up or pull-down resistors. The LVT family does not include bus-hold circuitry. Both families are 3.3 V low-voltage logic with 5 V tolerant inputs and outputs.
What are the operating voltage and drive current specifications for these devices?
Both the 74LVTH244MTC and 74LVT240MTCX operate from a 2.7 V to 3.6 V VCC supply. They provide ±32 mA output drive at 3.3 V, making them suitable for bus interface and backplane driving applications. These parameters are specified in the respective manufacturer datasheets.
Can the 74LVTH244MTC and 74LVT240MTCX be used in the same application interchangeably?
No, not interchangeably. The '244 provides non-inverting buffering, while the '240 provides inverting buffering. Additionally, the '244 includes bus-hold inputs while the '240 does not. The correct device must be selected based on the required logic polarity and whether bus-hold functionality is needed.
What package type do the 74LVTH244MTC and 74LVT240MTCX use?
Both devices are offered in a 20-pin TSSOP (Thin Shrink Small Outline Package). The 74LVTH244MTC is specified in the TSSOP-20 package, and the 74LVT240MTCX is also specified in the TSSOP-20 package. The "X" suffix on the 74LVT240MTCX typically indicates tape and reel packaging.
Do these devices have 5 V tolerant inputs and outputs?
Yes. Both the 74LVTH244MTC and 74LVT240MTCX feature 5 V tolerant inputs and outputs when VCC is within the specified operating range of 2.7 V to 3.6 V. This allows them to interface with 5 V logic systems without additional level-shifting circuitry.
What is the difference in propagation delay between the 74LVTH244MTC and 74LVT240MTCX?
Both devices have similar propagation delay characteristics because they are based on comparable LVT/LVTH process technology. The '244 and '240 differ primarily in logic function (non-inverting vs inverting) and bus-hold feature, not in speed grade. For exact propagation delay values, refer to the respective manufacturer datasheets, as timing may vary slightly between manufacturers and test conditions.