Microchip Technology 24LC65T-I/SM

Overview

24LC65T-I/SM from Microchip Technology Inc. is a 64 Kbit (8K × 8) I²C-compatible serial EEPROM with programmable high-endurance memory blocks, 64-byte input cache, and dual-speed I²C interface (100 kHz at 1.8–4.5 V, 400 kHz at 4.5–6.0 V). It operates from 2.5 V to 6.0 V, supports up to eight devices on one bus, and features Schmitt-trigger inputs and output slope control for noise immunity in industrial control and embedded data logging systems.

For engineers reviewing the 24LC65T-I/SM datasheet, 24LC65T-I/SM pinout, 24LC65T-I/SM application, or 24LC65T-I/SM equivalent, key selection considerations include its 2.5–6.0 V supply range, 400 kHz Fast Mode support, 10 million-cycle high-endurance block, programmable security for up to 15 × 4K blocks, and SOIJ-8 surface-mount package compatibility with legacy 24Cxx designs.

Technical Context

The 24LC65T-I/SM implements a two-wire I²C slave interface with hardware address pins A0–A2 enabling up to eight devices per bus. Its internal architecture includes an 8-page (64-byte) FIFO write cache, dual endurance memory mapping (10M cycles for one 4K block, 1M cycles for remaining 60K bits), and configurable security via dedicated configuration byte writes.

It uses advanced CMOS process with VDD monitor circuitry for power-on/off data protection, self-timed erase/write cycles, and Schmitt-triggered SCL/SDA inputs with 50 ns spike suppression. The device supports current-address, random, and sequential read modes, and acknowledges only after internal operations complete - requiring ACK polling for write completion detection.

Key Specifications

Pinout & Package

24LC65T-I/SM is housed in an 8-pin SOIJ (Small Outline Integrated Circuit, J-bend) surface-mount package, RoHS-compliant and rated for industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24LC65T-I/SM, 24AA65T-I/SM extends operational voltage down to 1.8 V without sacrificing features, while AT24C64D-SSHM-T trades programmable endurance/security for raw speed - making 24LC65T-I/SM the optimal choice for industrial systems requiring guaranteed 10M-cycle durability and hardware-enforced write protection.

Availability

24LC65T-I/SM is available at Aetrix Electronics and suitable for industrial sensor calibration storage, medical device configuration memory, and smart meter firmware parameter tables requiring stable component supply, long-lifecycle assurance, and RoHS-compliant sourcing.

Supply support for 24LC65T-I/SM 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 Inc. is a leading provider of microcontrollers, analog devices, and memory solutions, headquartered in Chandler, Arizona, with global design and manufacturing infrastructure.

The 24LC65T-I/SM belongs to Microchip's "Smart Serial EEPROM" product line, engineered specifically for applications demanding differentiated endurance, hardware security, and noise-immune I²C communication in harsh industrial and medical environments.

FAQ

What is the maximum I²C clock frequency supported by the 24LC65T-I/SM?

The 24LC65T-I/SM supports 100 kHz Standard Mode when VCC is between 1.8 V and 4.5 V, and 400 kHz Fast Mode when VCC is between 4.5 V and 6.0 V. Its datasheet specifies THIGH ≥ 600 ns and TLOW ≥ 1300 ns under Fast Mode conditions, confirming full compliance with I²C Fast Mode timing requirements. This dual-speed capability allows system designers to optimize bus performance based on supply voltage constraints.

Does the 24LC65T-I/SM include hardware write protection features?

Yes, the 24LC65T-I/SM provides programmable hardware write protection for up to 15 contiguous 4K-bit blocks using a one-time configurable security option. Once enabled, protected blocks cannot be overwritten via standard I²C writes - even during page or byte operations. This feature is implemented entirely in silicon and does not rely on software locks, making it suitable for safeguarding critical firmware parameters or calibration data against accidental or malicious corruption.

How does the 64-byte input cache improve write efficiency in the 24LC65T-I/SM?

The 64-byte input cache in the 24LC65T-I/SM allows up to 64 bytes of data to be loaded into an on-chip FIFO buffer before initiating the internal write cycle. This decouples bus transfer time from EEPROM programming latency, enabling burst writes at full I²C speed (up to 400 kHz) while hiding the 5 ms/page write delay. As a result, the effective write throughput increases significantly compared to byte-by-byte writes, especially in systems with tight real-time deadlines.

What is the endurance specification for the high-endurance memory block in the 24LC65T-I/SM?

The 24LC65T-I/SM includes one user-programmable 4K-bit block rated for 10,000,000 erase/write cycles at 25°C, while the remaining 60K bits are rated for 1,000,000 cycles. The high-endurance block location is set via configuration byte programming and defaults to address range 0x1E00–0x1FFF. This differentiated endurance model enables reliable storage of frequently updated variables - such as counters or runtime statistics - without compromising the longevity of static configuration data.

Is the 24LC65T-I/SM compatible with standard I²C protocol implementations?

Yes, the 24LC65T-I/SM fully complies with the industry-standard two-wire I²C bus protocol, including Start/Stop condition generation, 7-bit slave addressing (with A0–A2 hardware select), ACK/NACK signaling, and clock stretching behavior. It supports both current-address, random, and sequential read modes, and requires no special host-side drivers - integrating seamlessly with standard Linux i2c-dev, Arduino Wire, or STM32 HAL_I2C libraries without modification.