# AT25040B-SSHL-T

**Microchip Tech** · EEPROM · SOIC-8

AT25040B-SSHL-T from Microchip Tech, in a SOIC-8. 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 | CS | input | Chip Select: the device is selected when CS is low, and SO stays in high impedance while the device is not selected. |
| 2 | SO | output | Serial Data Output, which remains in a high-impedance state when the device is not selected or after an invalid opcode. |
| 3 | WP | input | Write Protect: when brought low, all write operations are inhibited, and WP must be held high during a WREN instruction. |
| 4 | GND | power_in | Ground reference for the device. |
| 5 | SI | input | Serial Data Input, which is ignored while SO is in the high-impedance state. |
| 6 | SCK | input | Serial Data Clock, which is always an input and sets the serial interface timing (up to 20MHz at 5V). |
| 7 | HOLD | input | Suspends serial communication when brought low while SCK is low, without resetting the serial sequence. |
| 8 | VCC | power_in | Power supply, specified from 1.8V to 5.5V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Microchip Tech |
| Package | SOIC-8 |
| Category | Memory |
| Pins | 8 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts |  | tin | U = Green, Matte Sn Lead Finish, | 13 |

## CAD (KiCad official)

- Symbol: `AT25040B-SSHL-T`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `at25040b-sshl-t-etched.step` / `at25040b-sshl-t-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `at25040b-sshl-t.step` / `at25040b-sshl-t.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Microchip Tech datasheet](docs/at25040b-sshl-t-datasheet.pdf) (23 pp, sha256 `4783c65c38abe35e`, retrieved 2026-10-28, 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/at25040b-sshl-t-datasheet.pdf)