HT25WD40ARZ from HTCSEMI, 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	SPI Chip Select (active low). When high, the device is deselected and DO is Hi-Z, drawing standby current. Must transition high-to-low after power-up before the first instruction is accepted; a pull-up on CS# is recommended so it tracks VCC during power-up.
2	DO/IO1	bidirectional	Serial Data Output in standard SPI mode; data is shifted out on the falling edge of CLK. Becomes bidirectional IO1 during Dual SPI (Fast Read Dual Output 3Bh) instructions.
3	WP#	input	Write Protect (active low). Used together with the Status Register SRP bit and Block Protect bits (BP2/BP1/BP0) to hardware-protect a portion or the entire memory array against write/erase operations.
4	VSS	power_in	Device ground reference (0 V).
5	DI/IO0	bidirectional	Serial Data Input in standard SPI mode; instructions, addresses, and data are latched on the rising edge of CLK. Becomes bidirectional IO0 during Dual SPI (Fast Read Dual Output 3Bh) instructions, shifting data out on the falling edge of CLK.
6	CLK	input	SPI Serial Clock Input. Provides the timing for all serial input and output operations. Supports SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1) up to 100 MHz.
7	NC	unconnected	No internal connection. Leave floating or tie to VSS.
8	VCC	power_in	Power supply pin, 1.65 V to 3.6 V (single-supply operation). Bypass with a 0.1 uF decoupling capacitor placed close to the pin.

Key specifications

Parameter	Value
Manufacturer	HTCSEMI
Package	SOP-8
Category	Memory
Pins	8

Ordering variants

Same part, different packaging or reel option.

HT25WD40ARZ

CAD (KiCad official)

Symbol: HT25WD40ARZ
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
`ht25wd40arz.step`	122 KB	You want the bare part, or you mark your own boards.
`ht25wd40arz-etched.step`	2.0 MB	You want the part with `HT25WD40ARZ` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 516 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: HTCSEMI datasheet (40 pp, sha256 19a05bc78a6d7123, 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