CAT25640VI-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	Chip Select (active-low). When high the device is deselected and SO is high-impedance; must be driven low to start any read or write command. Input capacitance ~8 pF.
2	SO	output	Serial Data Output. Data is shifted out MSB-first on the falling edge of SCK (SPI mode 0,0 or 1,1). Output capacitance ~8 pF; high-Z when CS is high or HOLD is asserted.
3	WP	input	Write Protect (active-low). When driven low and the WPEN bit is set, non-volatile status register writes and array writes are inhibited. Provides hardware write protection.
4	VSS	power_in	Ground reference for the device.
5	SI	input	Serial Data Input. Opcode, address and data are latched on the rising edge of SCK, MSB-first. Input capacitance ~8 pF.
6	SCK	input	Serial Clock. Supports SPI modes (0,0) and (1,1). Max 20 MHz at VCC = 4.5-5.5 V, 10 MHz at VCC >= 2.5 V, 5 MHz at VCC >= 1.8 V.
7	HOLD	input	Hold Transmission Input (active-low). Pausing SPI communication without deselecting the device; SO goes high-impedance and SI/SCK are ignored while HOLD is low.
8	VCC	power_in	Positive supply. Operating range 1.8 V to 5.5 V. Absolute max pin voltage VCC + 0.5 V (6.5 V max).

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

CAT25640VI-GT3
CAT25640VI-GT3V
CAT25640VI-GT3L
CAT25640VI-GT3Y
CAT25640VI-GT3HU4
CAT25640VI-GT3HU3
CAT25640VI-GT3VP2

CAD (KiCad official)

Symbol: CAT25640VI-GT3
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: onsemi datasheet (19 pp, sha256 66fe9e8a3e8b3ff2, 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