Microchip Technology AT24C64CY6-YH-T

Overview

AT24C64CY6-YH-T from Microchip Technology (formerly Atmel) is a 64 Kbit I²C-compatible serial EEPROM organized as 8192 × 8 bits, housed in an 8-lead Ultra Thin Mini-MAP (MLP2x3, 2.0 mm × 3.0 mm, 0.5 mm pitch) package with NiPdAu lead finish. It operates from 1.8 V to 5.5 V, supports up to 1 MHz clock at 5.0 V and 400 kHz at 1.8 V, and features hardware write protection via the WP pin. It is used for nonvolatile parameter storage in space-constrained industrial controllers and embedded sensor nodes.

For engineers reviewing the AT24C64CY6-YH-T datasheet, AT24C64CY6-YH-T pinout, AT24C64CY6-YH-T application, or AT24C64CY6-YH-T equivalent, key selection criteria include its 32-byte page write capability, 1 million write endurance, 100-year data retention, low-voltage operation down to 1.8 V, and compatibility with standard 2-wire bus topologies supporting up to eight devices.

Technical Context

The AT24C64CY6-YH-T implements a true 2-wire (I²C) interface with open-drain SDA and Schmitt-triggered SCL inputs, enabling noise-immune communication in electrically noisy environments. Its internal address counter supports current-address, random-address, and sequential read modes, while the cascading device addressing scheme uses A0–A2 pins to select one of eight possible addresses on a shared bus.

Write operations are internally self-timed with a maximum 5 ms cycle time; during this period, all inputs are disabled and acknowledge polling is required to detect completion. The WP pin provides hardware-level memory lockout by disabling writes when pulled high to VCC, independent of software control.

Key Specifications

Pinout & Package

AT24C64CY6-YH-T is packaged in an 8-lead Ultra Thin Mini-MAP (MLP2x3) dual no-lead package (JEDEC MO-229 compliant), measuring 2.0 mm × 3.0 mm with 0.5 mm pitch and NiPdAu lead finish. The thermal pad is optional and not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial EEPROM applications.

Compared with AT24C64D-SSHM-T and M24C64-WMN6TP, the AT24C64CY6-YH-T offers the smallest PCB footprint (2.0 × 3.0 mm), making it optimal for space-constrained portable electronics, while maintaining full functional equivalence in memory organization, timing, and interface protocol.

Availability

AT24C64CY6-YH-T is available at Aetrix Electronics and suitable for industrial PLCs, medical sensor modules, and automotive body control units requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for AT24C64CY6-YH-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology acquired Atmel in 2016 and continues to manufacture, qualify, and support the AT24Cxx family of serial EEPROMs with full backward compatibility and extended product longevity commitments.

The AT24C64CY6-YH-T belongs to Microchip's serial EEPROM product line, designed specifically for reliable, low-power, I²C-based nonvolatile data storage in space- and power-constrained embedded systems across industrial, medical, and automotive markets.

FAQ

What is the maximum I²C clock frequency supported by the AT24C64CY6-YH-T?

The AT24C64CY6-YH-T supports up to 1 MHz I²C clock frequency when operated at 5.0 V, and 400 kHz at 1.8 V. These values are specified in the AC Characteristics table of the official datasheet (Rev. 5298A). Exceeding these frequencies may result in timing violations and unreliable communication, especially under worst-case voltage and temperature conditions.

Does the AT24C64CY6-YH-T require external pull-up resistors on SDA and SCL lines?

Yes, the AT24C64CY6-YH-T requires external pull-up resistors on both SDA and SCL lines because its I²C interface uses open-drain outputs. Typical values range from 2.2 kΩ to 10 kΩ depending on bus capacitance and speed; 4.7 kΩ is commonly used for 400 kHz operation with moderate trace length. The AT24C64CY6-YH-T itself does not integrate internal pull-ups.

How is write protection implemented on the AT24C64CY6-YH-T?

Write protection on the AT24C64CY6-YH-T is implemented via the dedicated WP (Write Protect) pin. When WP is driven high to VCC, all write operations-including byte, page, and write-enable instructions-are inhibited. When WP is tied to GND, normal write functionality is enabled. Floating WP is internally pulled down, but Microchip recommends hardwiring for deterministic behavior.

What is the memory organization of the AT24C64CY6-YH-T?

The AT24C64CY6-YH-T contains 64 Kbits of EEPROM memory organized as 8192 words × 8 bits (8192 × 8). Internally, it is structured into 256 pages of 32 bytes each. This page architecture enables efficient 32-byte burst writes and defines the boundary for automatic address roll-over during sequential writes.

Is the AT24C64CY6-YH-T compatible with standard I²C protocols and controllers?

Yes, the AT24C64CY6-YH-T is fully compliant with the standard Phillips I²C bus specification, supporting START/STOP conditions, ACK/NACK handshaking, 7-bit device addressing (with A0–A2 inputs), and standard read/write sequences. It interoperates with any I²C master - including those in STM32, PIC, ESP32, and NXP microcontrollers - without protocol translation.