# SN74HCT245PWR

**Texas Instruments** · Buffer/Driver/Transceiver · TSSOP-20

SN74HCT245PWR from Texas Instruments, in a TSSOP-20. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | DIR | input | Direction select input. High = A to B, Low = B to A. TTL-compatible input (VIH ≥ 2 V, VIL ≤ 0.8 V). |
| 2 | A1 | bidirectional | Channel 1 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. ±6 mA drive at 5 V. |
| 3 | A2 | bidirectional | Channel 2 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 4 | A3 | bidirectional | Channel 3 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 5 | A4 | bidirectional | Channel 4 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 6 | A5 | bidirectional | Channel 5 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 7 | A6 | bidirectional | Channel 6 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 8 | A7 | bidirectional | Channel 7 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 9 | A8 | bidirectional | Channel 8 port A. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 10 | GND | power_in | Ground reference (0 V). Center-pin placement helps minimize high-speed switching noise. |
| 11 | B8 | bidirectional | Channel 8 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 12 | B7 | bidirectional | Channel 7 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 13 | B6 | bidirectional | Channel 6 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 14 | B5 | bidirectional | Channel 5 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 15 | B4 | bidirectional | Channel 4 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 16 | B3 | bidirectional | Channel 3 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 17 | B2 | bidirectional | Channel 2 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 18 | B1 | bidirectional | Channel 1 port B. Bidirectional bus I/O; direction set by DIR, tri-state when OE is high. |
| 19 | OE | input | Output enable, active low. High = all ports in high-impedance (isolation) mode; Low = all ports active. TTL-compatible input. |
| 20 | VCC | power_in | Positive supply voltage. Recommended 4.5 V to 5.5 V (nominal 5 V). Absolute max 7 V. |

## Key specifications

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

## Ordering variants

Same part, different packaging or reel option.

- `SN74HCT245PWR`
- `SN74HCT245PWRDW`
- `SN74HCT245PWRDWR`
- `SN74HCT245PWRN`
- `SN74HCT245PWRNE`
- `SN74HCT245PWRNS`
- `SN74HCT245PWRNSR`
- `SN74HCT245PWRDB`
- `SN74HCT245PWRDBR`
- `SN74HCT245PWRDGS`
- `SN74HCT245PWRDGSR`
- `SN74HCT245PWRJ`
- `SN74HCT245PWRW`
- `SN74HCT245PWRFK`

## CAD (KiCad official)

- Symbol: `SN74HCT245PWR`
- Footprint: `Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm`
- 3D model: TSSOP-20 (KiCad packages3D, STEP)
- 3D model files: `sn74hct245pwr-etched.step` / `sn74hct245pwr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sn74hct245pwr.step` / `sn74hct245pwr.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`sn74hct245pwr.step`](sn74hct245pwr.step) | 267 KB | You want the bare part, or you mark your own boards. |
| [`sn74hct245pwr-etched.step`](sn74hct245pwr-etched.step) | 2.9 MB | You want the part with `SN74HCT245PWR` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 742 faces against 327 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

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

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/lit/ds/symlink/sn74hct245.pdf) (38 pp, sha256 `17db29398bd94ccf`, retrieved 2026-08-17, tier: manufacturer)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/sn74hct245pwr-datasheet.pdf)