# 74AC244MTCX

**onsemi** · Buffers, Drivers, Receivers, Transceivers · TSSOP-20

74AC244MTCX from onsemi, in a TSSOP-20. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | OE1 | input | Active-low 3-STATE output enable input for the first buffer group, controlling outputs O0-O3 on pins 18, 16, 14, 12. |
| 2 | I0 | input | Data input I0, buffered to output O0 when OE1 is low. |
| 3 | O4 | tri_state | 3-STATE output O4, enabled by OE2 and driven from I4, sources/sinks 24mA. |
| 4 | I1 | input | Data input I1, buffered to output O1 when OE1 is low. |
| 5 | O5 | tri_state | 3-STATE output O5, enabled by OE2 and driven from I5, sources/sinks 24mA. |
| 6 | I2 | input | Data input I2, buffered to output O2 when OE1 is low. |
| 7 | O6 | tri_state | 3-STATE output O6, enabled by OE2 and driven from I6, sources/sinks 24mA. |
| 8 | I3 | input | Data input I3, buffered to output O3 when OE1 is low. |
| 9 | O7 | tri_state | 3-STATE output O7, enabled by OE2 and driven from I7, sources/sinks 24mA. |
| 10 | GND | power_in | Ground pin. |
| 11 | I7 | input | Data input I7, buffered to output O7 when OE2 is low. |
| 12 | O3 | tri_state | 3-STATE output O3, enabled by OE1 and driven from I3, sources/sinks 24mA. |
| 13 | I6 | input | Data input I6, buffered to output O6 when OE2 is low. |
| 14 | O2 | tri_state | 3-STATE output O2, enabled by OE1 and driven from I2, sources/sinks 24mA. |
| 15 | I5 | input | Data input I5, buffered to output O5 when OE2 is low. |
| 16 | O1 | tri_state | 3-STATE output O1, enabled by OE1 and driven from I1, sources/sinks 24mA. |
| 17 | I4 | input | Data input I4, buffered to output O4 when OE2 is low. |
| 18 | O0 | tri_state | 3-STATE output O0, enabled by OE1 and driven from I0, sources/sinks 24mA. |
| 19 | OE2 | input | Active-low 3-STATE output enable input for the second buffer group, controlling outputs O4-O7 on pins 3, 5, 7, 9. |
| 20 | VCC | power_in | Positive supply voltage pin. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | TSSOP-20 |
| Category | Logic |
| Pins | 20 |

## CAD (KiCad official)

- Symbol: `74AC244MTCX`
- Footprint: `Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm`
- 3D model: TSSOP-20 (KiCad packages3D, STEP)
- 3D model files: `74ac244mtcx-etched.step` / `74ac244mtcx-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `74ac244mtcx.step` / `74ac244mtcx.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [onsemi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588930477974048768) (14 pp, sha256 `2e2a222a0cf8049a`, retrieved 2026-10-21, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (vision), consensus `claude-opus-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/74ac244mtcx-datasheet.pdf)