HG24C128MM 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. Hardwired to VCC or GND to set part of the 3-bit I2C device address, allowing up to 8 devices on a bus. Internally biased to a logic low if left floating (when VCC-plane coupling is <3 pF); tie to GND for coupling >3 pF.
2	A1	input	Device address input bit 1. Hardwired to VCC or GND to set part of the 3-bit I2C device address. Internally biased to a logic low if left floating (when VCC-plane coupling is <3 pF); tie to GND for coupling >3 pF.
3	NC	unconnected	No connect. Leave unconnected.
4	GND	power_in	Ground reference for the device.
5	SDA	bidirectional	Serial data line for the two-wire (I2C) interface. Bi-directional, open-drain output requiring an external pull-up resistor; may be wire-ORed with other open-drain/open-collector devices.
6	SCL	input	Serial clock input for the two-wire (I2C) interface. Positive edge clocks data into the EEPROM and negative edge clocks data out. Supports 1 MHz at 5V and 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 (hardware data protection). Internally biased to a logic low if left floating (VCC-plane coupling <3 pF); tie to GND for coupling >3 pF.
8	VCC	power_in	Positive supply voltage input. Operating range 1.8V to 5.5V. Standby current ISB = 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.

HG24C128MM/TR
HG24C128MMM/TR
HG24C128MMN

CAD (KiCad official)

Symbol: HG24C128MM
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