# 25LC128-E

**Microchip Tech** · EEPROM · SOIC-8

25LC128-E 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 input: a low level selects the device, a high level deselects it and forces Standby mode, and SO goes high-impedance when deselected. |
| 2 | SO | tri_state | Serial data output that shifts data out after the falling edge of SCK during a read, and goes high-impedance when the device is deselected or HOLD is low. |
| 3 | WP | input | Write-protect pin that, with WPEN set high and WP low, disables writes to the nonvolatile bits of the STATUS register. |
| 4 | VSS | power_in | Ground. |
| 5 | SI | input | Serial data input that receives instructions, addresses and data, latched on the rising edge of SCK. |
| 6 | SCK | input | Serial clock input that synchronizes communication; SI is latched on the rising edge and SO updates after the falling edge. |
| 7 | HOLD | input | Hold input that pauses serial communication without resetting the sequence when pulled low while SCK is low, and must be held high when not used. |
| 8 | VCC | power_in | Supply voltage, 2.5V to 5.5V for the 25LC128 (absolute maximum 6.5V). |

## 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 | 8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC] A A2 | 21 |

## CAD (KiCad official)

- Symbol: `25LC128-E`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `25lc128-e-etched.step` / `25lc128-e-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `25lc128-e.step` / `25lc128-e.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Microchip Tech datasheet](docs/25lc128-e-datasheet.pdf) (35 pp, sha256 `fe26fc9dad487854`, retrieved 2026-10-30, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-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/25lc128-e-datasheet.pdf)