Microchip Technology 24C65T-I/SM

Overview

24C65T-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 across 4.5–6.0 V supply and supports industrial temperature range (−40°C to +85°C) in SOIJ-8 package. Used for firmware parameter storage in embedded controllers requiring frequent updates to critical configuration data.

For engineers reviewing the 24C65T-I/SM datasheet, 24C65T-I/SM pinout, 24C65T-I/SM application, or 24C65T-I/SM equivalent, key selection considerations include its 10 million-cycle high-endurance block, Schmitt-triggered noise-immune I²C interface, programmable security for up to 15 × 4K blocks, 2 ms typical byte write time, and compatibility with multi-device I²C bus topologies supporting up to 512 Kbits total.

Technical Context

The 24C65T-I/SM implements a two-wire I²C slave interface with hardware-addressable device select pins (A0–A2), enabling up to eight devices on one bus. Its internal architecture includes an 8-page (64-byte) FIFO write cache, address pointer auto-increment logic, and separate high-endurance (10M E/W cycles) and standard-endurance (1M E/W cycles) memory blocks mapped via configurable S/HE bit.

It features integrated V_CC monitoring for power-fail write protection, self-timed erase/write cycles, and Schmitt-triggered, filtered SDA/SCL inputs with 50 ns spike suppression - ensuring robust operation in electrically noisy industrial environments without external filtering components.

Key Specifications

Pinout & Package

8-pin SOIJ (Small Outline Integrated Circuit, J-bend) surface-mount package, RoHS-compliant, with 1.27 mm pitch and moisture sensitivity level (MSL) 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C64D-SSHM-T and BR24G64FJ-WE2, the 24C65T-I/SM uniquely delivers field-programmable 10M-cycle memory and one-time configurable security - making it the only choice for industrial systems requiring both frequent parameter updates and firmware-level data protection without MCU-side software overhead.

Availability

24C65T-I/SM is available at Aetrix Electronics and suitable for industrial control systems, medical diagnostics equipment, automotive body electronics, and smart energy metering applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for 24C65T-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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and memory solutions for industrial, automotive, and communications markets.

The 24C65T-I/SM belongs to Microchip's "Smart Serial EEPROM" product line, designed specifically for systems needing differentiated endurance, configurable security, and noise-resilient I²C communication in harsh operating environments.

FAQ

What is the maximum I²C clock frequency supported by the 24C65T-I/SM?

The 24C65T-I/SM supports 400 kHz fast-mode I²C operation when V_CC is between 4.5 V and 6.0 V. At lower voltages (below 4.5 V), it defaults to 100 kHz standard mode. This dual-speed capability is hardware-determined by supply voltage and requires no software configuration. The 24C65T-I/SM maintains full AC timing compliance - including 600 ns minimum THIGH and TLOW - at 400 kHz under industrial temperature conditions.

Does the 24C65T-I/SM include hardware write protection?

Yes, the 24C65T-I/SM provides hardware-based write protection through its programmable security feature. Users can permanently configure up to 15 contiguous 4K-bit blocks to be write-protected using a one-time programming sequence. Once set, the protection cannot be disabled or modified. This differs from simple WP pin-based schemes because it operates at the memory-block level and persists across power cycles - a key capability implemented in the 24C65T-I/SM's internal control logic.

How does the 64-byte input cache improve system performance in the 24C65T-I/SM?

The 64-byte input cache in the 24C65T-I/SM allows the host MCU to stream up to 64 bytes of data over I²C before triggering the internal write cycle. This decouples bus transfer time from EEPROM programming latency, enabling full-bandwidth I²C utilization and reducing host wait states. For example, writing 64 bytes takes ~5 ms total (one page), versus 128 ms for 64 individual byte writes - a 25× throughput improvement realized directly by the 24C65T-I/SM's cache architecture.

What is the purpose of the NC pin on the 24C65T-I/SM SOIJ-8 package?

Pin 6 on the 24C65T-I/SM SOIJ-8 package is designated NC (No Connection) and has no internal bond wire or circuit connection. It must remain electrically floating - no PCB trace, solder joint, or pull-up/down resistor should be attached. This pin exists for mechanical symmetry and package compatibility within Microchip's 8-pin SOIJ family; its presence does not affect 24C65T-I/SM functionality, timing, or reliability, and omitting it from layout does not compromise performance.

Can the high-endurance block in the 24C65T-I/SM be relocated after initial programming?

No - the location of the high-endurance (10M-cycle) block in the 24C65T-I/SM is programmable only once, and only before any security blocks are configured. If security is enabled with length >0, the high-endurance block location becomes fixed and immutable. The default location is the highest 4K block (0x1E00–0x1FFF). Relocation attempts after security programming will be ignored by the 24C65T-I/SM's internal state machine, preserving data integrity and preventing unintended configuration conflicts.