# SN74LS156NSR

**Texas Instruments** · Signal Switches, Multiplexers, Decoders · SO-16

SN74LS156NSR from Texas Instruments, in a SO-16. 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 | 1C | input | Data input for section 1; data applied at 1C is inverted at the 1Y outputs. |
| 2 | 1G | input | Active-low strobe (enable) input for section 1. |
| 3 | B | input | Binary-address select input common to both sections. |
| 4 | 1Y3 | output | Open-collector output 3 of section 1. |
| 5 | 1Y2 | output | Open-collector output 2 of section 1. |
| 6 | 1Y1 | output | Open-collector output 1 of section 1. |
| 7 | 1Y0 | output | Open-collector output 0 of section 1. |
| 8 | GND | power_in | Ground. |
| 9 | 2Y0 | output | Open-collector output 0 of section 2. |
| 10 | 2Y1 | output | Open-collector output 1 of section 2. |
| 11 | 2Y2 | output | Open-collector output 2 of section 2. |
| 12 | 2Y3 | output | Open-collector output 3 of section 2. |
| 13 | A | input | Binary-address select input common to both sections. |
| 14 | 2G | input | Active-low strobe (enable) input for section 2. |
| 15 | 2C | input | Active-low data input for section 2; data applied at 2C is not inverted through its outputs. |
| 16 | VCC | power_in | Positive supply voltage. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SO-16 |
| Category | Logic |
| Pins | 16 |

## CAD (KiCad official)

- Symbol: `SN74LS156NSR`
- Footprint: `Package_SO:SOIC-16_3.9x9.9mm_P1.27mm`
- 3D model: SO-16 (KiCad packages3D, STEP)
- 3D model files: `sn74ls156nsr-etched.step` / `sn74ls156nsr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `sn74ls156nsr.step` / `sn74ls156nsr.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/cn/lit/gpn/sn74ls156) (22 pp, sha256 `893a930eaec60d8f`, retrieved 2026-10-08, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+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/sn74ls156nsr-datasheet.pdf)