A 64 Kbit (8 KB) serial EEPROM with an I2C interface, in SO-8, ST's take on the ubiquitous 24-series EEPROM and a staple for storing settings, calibration, and small logs that survive power loss. It talks I2C at up to 1 MHz, writes in 32-byte pages, and rates over a million write/erase cycles with 200-year retention. Three chip-address pins (E0-E2) put up to eight on one bus, and a write-control pin (WC) hardware-protects the array against stray writes. It shares its pinout and command set with the 24LC64/AT24C64. Runs 1.7-5.5 V.

Pinout

Pin	Name	Type	Function
1	E0	input	Chip enable address input bit 0. Tied to VCC or VSS to set b1 of the 7-bit I2C device select code. Left floating reads as 0.
2	E1	input	Chip enable address input bit 1. Tied to VCC or VSS to set b2 of the 7-bit I2C device select code. Left floating reads as 0.
3	E2	input	Chip enable address input bit 2. Tied to VCC or VSS to set b3 of the 7-bit I2C device select code. Left floating reads as 0.
4	VSS	power_in	Ground reference for all signals, including VCC supply voltage.
5	SDA	bidirectional	I2C serial data. Open-drain bidirectional line for address, data and acknowledge transfers. Requires an external pull-up resistor to VCC.
6	SCL	input	I2C serial clock input. Strobes data in on SDA and clocks data out on SDA. Supports 100 kHz, 400 kHz, and 1 MHz bus speeds.
7	WC	input	Write control, active low. When driven high, all write operations to the memory array are disabled (device ACKs the device-select and address bytes but not data bytes). Low or floating enables writes.
8	VCC	power_in	Supply voltage. 1.7 V to 5.5 V for M24C64-F/DF (down to 1.6 V under restricting conditions), 1.8 V to 5.5 V for M24C64-R, 2.5 V to 5.5 V for M24C64-W. Recommend 10 nF to 100 nF decoupling to VSS close to the pin.

Key specifications

Parameter	Value
Type	Serial EEPROM (non-volatile)
Density	64 Kbit (8 KB)
Interface	I2C up to 1 MHz
Write	32-byte page
Endurance	1,000,000+ cycles
Retention	>200 years
Addressing	E0-E2 (8 per bus) + WC protect
Supply voltage	1.7-5.5 V
Package	SO-8

Ordering variants

Same part, different packaging or reel option.

M24C64-DFMN6TP (SO-8)
M24C64-RMN6TP (SO-8)

CAD (KiCad official)

Symbol: M24C64 (generated from datasheet; KiCad has no symbol)
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D)

Provenance

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

Datasheet: STMicroelectronics datasheet (50 pp, sha256 c95123bad692fd89, retrieved 2026-08-17, tier: manufacturer)
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