Microchip Technology 24C65-I/SM

Overview

24C65-I/SM from Microchip Technology 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 industrial temperature (−40°C to +85°C), supports up to eight devices on one bus, and features Schmitt-trigger inputs for noise immunity in embedded control and sensor calibration systems.

For engineers reviewing the 24C65-I/SM datasheet, 24C65-I/SM pinout, 24C65-I/SM application, or 24C65-I/SM equivalent, key selection criteria include its 4.5–6.0 V supply range, 5 ms/page write cycle, 10 million-cycle high-endurance block, security-programmable 4K-block protection, and SOIJ-8 surface-mount package compatibility with legacy 24Cxx footprints.

Technical Context

The 24C65-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 registers that lock write access to up to 15 contiguous 4K blocks.

It uses advanced CMOS process with V_DD monitor circuitry for power-fail write protection, Schmitt-triggered SCL/SDA inputs with 50 ns spike suppression, and output slope control to minimize ground bounce. The device requires no external components beyond standard I²C pull-ups and supports current-address, random, and sequential read modes without host intervention.

Key Specifications

Pinout & Package

24C65-I/SM is housed in an 8-pin SOIJ (Small Outline Integrated Circuit, J-bend) surface-mount package, compatible with industry-standard SOIC-8 footprints but with gull-wing leads replaced by J-leads for improved moisture resistance and reflow reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 24C65-I/SM, 24LC65-I/SM extends low-voltage usability but sacrifices the strict 4.5–6.0 V optimization and associated noise immunity; AT24C64D-SSHM-T offers higher speed and broader voltage range but omits endurance partitioning and security-making 24C65-I/SM uniquely suited for industrial firmware/data integrity use cases.

Availability

24C65-I/SM is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical device manufacturing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for 24C65-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 nonvolatile memory solutions for embedded control applications.

The 24C65-I/SM belongs to Microchip's legacy 24XX65 "Smart Serial EEPROM" product line, engineered for systems demanding programmable endurance, hardware-based security, and robust I²C operation in harsh electrical environments.

FAQ

What is the maximum I²C clock frequency supported by the 24C65-I/SM?

The 24C65-I/SM supports up to 400 kHz I²C Fast Mode-but only when V_CC is within 4.5 V to 6.0 V. Below 4.5 V, it defaults to Standard Mode (100 kHz). This voltage-gated speed behavior is hardwired and cannot be overridden in firmware. The 24C65-I/SM datasheet specifies strict timing margins (e.g., 600 ns minimum THIGH) that must be met at 400 kHz to ensure reliable communication.

Can the 24C65-I/SM be used in a 3.3 V system?

No-the 24C65-I/SM requires a minimum V_CC of 4.5 V and is not rated for 3.3 V operation. Attempting to power it at 3.3 V will result in undefined behavior, failed I²C acknowledgments, and potential data corruption. For 3.3 V systems, consider the 24LC65-I/SM (2.5–6.0 V) or AT24C64D-SSHM-T (1.7–5.5 V) as alternatives with verified low-voltage functionality.

How does the high-endurance block work in the 24C65-I/SM?

The 24C65-I/SM includes one programmable 4K-bit block rated for 10 million erase/write cycles, distinct from the standard 1 million-cycle endurance of the remaining 60K bits. Its location is set via configuration byte bit S/HE=0 and upper address bits; once programmed, it persists across power cycles. The high-endurance block takes precedence over security settings-if both overlap, endurance behavior is retained.

Is the 24C65-I/SM pin-compatible with other 24Cxx EEPROMs in SOIJ-8?

Yes-the 24C65-I/SM uses the standard 8-pin SOIJ-8 footprint and identical pinout (A0–A2, VSS, SDA, SCL, VCC, NC) as 24C01 through 24C512 family members. However, software compatibility requires verifying I²C address mapping (1010xxx), page size (8 bytes), and timing constraints-especially since 24C65-I/SM enforces stricter V_CC and AC specs than earlier variants.

Does the 24C65-I/SM support write protection without external hardware?

Yes-the 24C65-I/SM includes on-chip, one-time-programmable security registers that can lock write access to 0–15 contiguous 4K blocks. Once enabled, protection persists permanently and cannot be disabled. This eliminates the need for external WP pins or GPIO-controlled gating, simplifying PCB layout and enhancing tamper resistance in certified medical or industrial systems.