MD25Q128SIG from GigaDevice Semicon Beijing, in a SOIC-8-208mil. 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 input, active low. Must be driven high when the chip is not selected; do not leave floating after power-on. Enables the SPI interface and starts a command sequence on the falling edge.
2	SO/IO1	bidirectional	Serial Data Output in Standard SPI mode; becomes bidirectional data line IO1 in Dual/Quad SPI modes. Data shifts out on the falling edge of SCLK in Standard SPI.
3	WP#/IO2	bidirectional	Write Protect input, active low, when QE=0. When the Quad Enable (QE) bit in the Status Register is set, the pin acts as bidirectional data line IO2 for Quad SPI commands.
4	VSS	power_in	Ground reference for the device.
5	SI/IO0	bidirectional	Serial Data Input in Standard SPI mode; becomes bidirectional data line IO0 in Dual/Quad SPI modes. Input data is latched on the rising edge of SCLK in Standard SPI.
6	SCLK	input	Serial Clock input. Provides the timing for serial input and output operations. SPI modes 0 and 3 are supported, up to 104 MHz for Standard/Dual SPI fast read.
7	HOLD#/RESET#/IO3	bidirectional	Configurable pin: acts as HOLD# (pauses serial communication, active low) or RESET# (hardware reset, active low) when QE=0, based on the HOLD/RST status register bit. Becomes bidirectional data line IO3 for Quad SPI commands when QE=1.
8	VCC	power_in	Single power supply input, 2.7V to 3.6V (nominal 3.3V). Powers all internal logic and flash core operations; typical active current 25mA, standby/deep-power-down current 5uA max.

Key specifications

Parameter	Value
Manufacturer	GigaDevice Semicon Beijing
Package	SOIC-8-208mil
Category	Memory
Pins	8

Ordering variants

Same part, different packaging or reel option.

MD25Q128SIG
MD25Q128SIGVIG
MD25Q128SIGPIG
MD25Q128SIGFIG
MD25Q128SIGFIR
MD25Q128SIGWIG
MD25Q128SIGYIG

CAD (KiCad official)

Symbol: MD25Q128SIG
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8-208mil (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`md25q128sig.step`	122 KB	You want the bare part, or you mark your own boards.
`md25q128sig-etched.step`	2.5 MB	You want the part with `MD25Q128SIG` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 602 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: GigaDevice Semicon Beijing datasheet (55 pp, sha256 bfbd498bf3a5d54d, 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