AT25640B-SSHL-T from Microchip, in a SOIC-8. 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	CS	input	Chip Select, active-low. Drives the device into the active state when low, enabling the SPI interface; when high, the device is deselected and SO is high-impedance.
2	SO	output	Serial Data Output. Tri-state output; shifts data out on the falling edge of SCK. High-impedance when CS is high.
3	WP	input	Write Protect, active-low. When low with WPEN=1, blocks writes to the status register (hardware write protection); when high, normal read/write operations proceed. Function disabled when WPEN=0.
4	GND	power_in	Ground reference for all logic and supply.
5	SI	input	Serial Data Input. Data is shifted in MSB-first on the rising edge of SCK when CS is low.
6	SCK	input	Serial Clock. Supports SPI Modes 0 (0,0) and 3 (1,1). Max 20MHz at 5V, 10MHz at 2.5V, 5MHz at 1.8V.
7	HOLD	input	Hold, active-low. Suspends serial communication without resetting the internal sequence; SO enters high-impedance and SI is ignored while HOLD is low. Must be transitioned only while SCK is low.
8	VCC	power_in	Supply voltage, 1.8V to 5.5V. Standby current typ 2.0µA at 5V; active current typ 7.5mA reading at 20MHz/5V.

Key specifications

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

Ordering variants

AT25640B-SSHL-T

CAD (KiCad official)

Symbol: AT25640B-SSHL-T
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`at25640b-sshl-t.step`	122 KB	You want the bare part, or you mark your own boards.
`at25640b-sshl-t-etched.step`	2.7 MB	You want the part with `AT25640B-SSHL-T` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 665 faces against 147 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: Microchip datasheet (23 pp, sha256 6eb63f39b2e61b60, 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