# SN74AHC245QPWR

**Texas Instruments** · Buffers, Drivers, Receivers, Transceivers · TSSOP-20

SN74AHC245QPWR from Texas Instruments, 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 | DIR | input | Direction-control input that selects A-to-B transmission when high and B-to-A transmission when low; the DIR input is specified for 0 V to 5.5 V. |
| 2 | A1 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 3 | A2 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 4 | A3 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 5 | A4 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 6 | A5 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 7 | A6 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 8 | A7 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 9 | A8 | bidirectional | A-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 10 | GND | power_in | Ground reference pin. |
| 11 | B8 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 12 | B7 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 13 | B6 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 14 | B5 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 15 | B4 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 16 | B3 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 17 | B2 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 18 | B1 | bidirectional | B-bus data input/output, with I/O voltage limited to 0 V to VCC per the recommended operating conditions. |
| 19 | OE | input | Output-enable input; when high the buses are isolated, and it should be tied to VCC through a pullup resistor to hold the high-impedance state during power up or down, with input range 0 V to 5.5 V. |
| 20 | VCC | power_in | Supply voltage, specified from 2 V to 5.5 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | TSSOP-20 |
| Category | Logic |
| Pins | 20 |

## CAD (KiCad official)

- Symbol: `SN74AHC245QPWR`
- Footprint: `Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm`
- 3D model: TSSOP-20 (KiCad packages3D, STEP)
- 3D model files: `sn74ahc245qpwr-etched.step` / `sn74ahc245qpwr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sn74ahc245qpwr.step` / `sn74ahc245qpwr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/sn74ahc245q.pdf) (17 pp, sha256 `2984f9f0efcb7078`, retrieved 2026-10-10, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-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/sn74ahc245qpwr-datasheet.pdf)