FM25Q04B-SO-T-G from FUDAN MICRO, in a SOP-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 input. When high, device is deselected and DO/DQ pins are high-impedance; when low, device is enabled and instructions can be written / data read. Must track VCC at power-up; a pull-up resistor to VCC is recommended.
2	DO/DQ1	bidirectional	Standard SPI Serial Data Output (DO); becomes bidirectional DQ1 in Dual SPI, Quad SPI, and QPI modes. Data is shifted out on the falling edge of CLK in Standard SPI mode.
3	WP#/DQ2	bidirectional	Active-low Write Protect input for Standard/Dual SPI, used with the Status Register block-protect bits and SRP to hardware-protect part or all of the array. Becomes bidirectional DQ2 when the Quad Enable (QE) bit in Status Register-2 is set for Quad SPI / QPI operation.
4	VSS	power_in	Device ground reference (0 V).
5	DI/DQ0	bidirectional	Standard SPI Serial Data Input (DI); becomes bidirectional DQ0 in Dual SPI, Quad SPI, and QPI modes. Instructions, addresses, and data are shifted in on the rising edge of CLK in Standard SPI mode.
6	CLK	input	SPI Serial Clock input; provides timing for all serial input and output operations. Supports SPI Mode 0 and Mode 3, up to 100 MHz for FAST_READ and 50 MHz for standard READ.
7	HOLD#/DQ3	bidirectional	Active-low Hold input for Standard/Dual SPI - when driven low with CS# low, pauses serial communication (DO becomes high-Z, DI/CLK ignored). Becomes bidirectional DQ3 when QE=1 for Quad SPI / QPI operation; HOLD# function is unavailable in Quad modes.
8	VCC	power_in	Positive supply voltage input, 2.3 V to 3.6 V single-supply operation. Decouple with a bypass capacitor close to the pin.

Key specifications

Parameter	Value
Manufacturer	FUDAN MICRO
Package	SOP-8
Category	Memory
Pins	8

Ordering variants

Same part, different packaging or reel option.

FM25Q04B-SO-T-G

CAD (KiCad official)

Symbol: FM25Q04B-SO-T-G
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`fm25q04b-so-t-g.step`	122 KB	You want the bare part, or you mark your own boards.
`fm25q04b-so-t-g-etched.step`	2.7 MB	You want the part with `FM25Q04B-SO-T-G` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 657 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: FUDAN MICRO datasheet (69 pp, sha256 d930695cfb844a82, retrieved 2026-08-17, tier: lcsc)
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