AT24C256CM from HGSEMI, 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	E0	input	Device address input bit 0. Hard-wired to VCC or GND to set the least-significant bit of the 7-bit I2C slave address, allowing up to eight AT24C256C devices on the same bus. Schmitt-trigger CMOS input.
2	E1	input	Device address input bit 1. Hard-wired to VCC or GND to set one of the three slave-address selection bits (E2, E1, E0). Schmitt-trigger CMOS input.
3	E2	input	Device address input bit 2. Hard-wired to VCC or GND to set the most-significant slave-address selection bit. Schmitt-trigger CMOS input.
4	GND	power_in	Ground reference for the power supply. Must be tied to system ground.
5	SDA	bidirectional	Serial data. Open-drain bidirectional I2C data line; requires an external pull-up resistor to VCC. Data is latched on the rising edge of SCL and driven out on the falling edge.
6	SCL	input	Serial clock input. Provides the clock reference for the 2-wire I2C interface; supports Standard (100 kHz), Fast (400 kHz), and High-Speed (1 MHz) modes. Schmitt-trigger input with integrated spike-suppression filter.
7	WP	input	Write-Protect input. Tie to VCC to hardware write-protect the entire memory array (device becomes read-only); tie to GND or leave floating to enable normal write operations.
8	VCC	power_in	Device power supply, 1.7 V to 5.5 V. Recommend a 100 nF ceramic decoupling capacitor between VCC and GND close to the pin. Standby current <1 uA typical.

Key specifications

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

Ordering variants

AT24C256CM/TR
AT24C256CMCN
AT24C256CMM/TR
AT24C256CMT/TR

CAD (KiCad official)

Symbol: AT24C256CM
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
`at24c256cm.step`	122 KB	You want the bare part, or you mark your own boards.
`at24c256cm-etched.step`	2.0 MB	You want the part with `AT24C256CM` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 506 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: HGSEMI datasheet (25 pp, sha256 fc01506b5cd4c437, 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