HG24C256MM from HGSEMI, in a MSOP-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	A0	input	Device address input bit 0. Hardwire to VCC or GND to set the device's chip-select address, allowing up to four/eight 24Cxx devices on one I2C bus. Internally pulled to GND when floating (if board VCC-plane coupling <3 pF); otherwise tie to GND.
2	A1	input	Device address input bit 1. Hardwire to VCC or GND to set the device's chip-select address. Internally pulled to GND when floating (if board VCC-plane coupling <3 pF); otherwise tie to GND.
3	NC	unconnected	No connect. Leave floating or tie to GND.
4	GND	power_in	Ground reference for the device.
5	SDA	bidirectional	Serial data. Bi-directional open-drain line for I2C data transfer; requires an external pull-up resistor to VCC. May be wire-ORed with other open-drain/open-collector devices.
6	SCL	input	Serial clock input. Positive edge clocks data into the EEPROM; negative edge clocks data out. Max 1 MHz at 5V, 400 kHz at 1.8/2.7/3.3V.
7	WP	input	Write protect input. Tie to GND for normal read/write; tie to VCC to inhibit all writes to the memory array (full array hardware write protect). Internally pulled to GND when floating (if VCC-plane coupling <3 pF); otherwise tie to GND.
8	VCC	power_in	Power supply input. Operating range 1.8V to 5.5V; absolute max 6.5V. Standby current typ. 3 µA at 5.5V.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

HG24C256MM/TR
HG24C256MMM/TR
HG24C256MMN

CAD (KiCad official)

Symbol: HG24C256MM
Footprint: Package_SO:MSOP-8_3x3mm_P0.65mm
3D model: MSOP-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: HGSEMI datasheet (14 pp, sha256 a9630ce0b45ca10b, 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