CAT25256VI-GT3 from onsemi, 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	Active-low SPI Chip Select. A high-to-low transition on CS selects the device and initiates a new instruction sequence; a low-to-high transition deselects it and forces the SO output to high-impedance. Must be held high during standby to minimize supply current.
2	SO	output	Serial Data Output. Data is shifted out on the falling edge of SCK (MSB first). High-impedance when CS is high or when the device is in HOLD.
3	WP	input	Active-low Write Protect. When held low together with the WPEN bit in the status register set, the status register is hardware write-protected, preventing changes to the block protection bits. Tie to VCC if unused.
4	VSS	power_in	Ground reference for all supply and signal levels (0 V).
5	SI	input	Serial Data Input. Op-codes, addresses and data are shifted in on the rising edge of SCK (MSB first).
6	SCK	input	SPI Serial Clock input. Supports SPI modes (0,0) and (1,1) up to 20 MHz at VCC >= 4.5 V (10 MHz at VCC >= 2.5 V, 5 MHz at VCC < 2.5 V).
7	HOLD	input	Active-low Hold input. Pausing serial communication without deselecting the device; when low (with CS low) SO goes high-Z and SI/SCK are ignored. Tie to VCC if unused.
8	VCC	power_in	Positive supply voltage, 1.8 V to 5.5 V. Typical read current 0.8-3.0 mA depending on VCC/frequency; standby current 1-5 uA.

Key specifications

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

Ordering variants

CAT25256VI-GT3
CAT25256VI-GT3VE-GT3
CAT25256VI-GT3LI-G
CAT25256VI-GT3XI-T2
CAT25256VI-GT3XE-T2
CAT25256VI-GT3YI-G
CAT25256VI-GT3YI-GT3
CAT25256VI-GT3HU4I-GT3

CAD (KiCad official)

Symbol: CAT25256VI-GT3
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
`cat25256vi-gt3.step`	122 KB	You want the bare part, or you mark your own boards.
`cat25256vi-gt3-etched.step`	2.6 MB	You want the part with `CAT25256VI-GT3` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 635 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: onsemi datasheet (18 pp, sha256 15c84e62f165bfbe, 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