Renesas RM24C256DS-LMAI-T

Overview

RM24C256DS-LMAI-T from Adesto Technologies is a 256Kbit serial EEPROM memory IC using CBRAM® resistive non-volatile technology, operating from 1.65V to 3.6V with I²C interface up to 1 MHz, 64-byte page size, and integrated 128-byte OTP security register. It delivers ultra-low-energy byte writes (50 nJ), 100,000 write cycles, and >40-year data retention at 125°C - deployed in industrial sensor nodes requiring secure, low-power configuration storage.

For engineers reviewing the RM24C256DS-LMAI-T datasheet, RM24C256DS-LMAI-T pinout, RM24C256DS-LMAI-T application, or RM24C256DS-LMAI-T equivalent, key selection criteria include I²C timing compliance at 1 MHz, WP-controlled hardware write protection, E0–E2 addressable multi-device bus topology, OTP register partitioning (64B factory ID + 64B user-programmable), and CBRAM-specific endurance behavior across temperature.

Technical Context

This device implements a slave-only I²C interface with SDA (open-drain) and SCL (input-only) pins, supporting standard-mode (100 kHz), fast-mode (400 kHz), and fast-mode plus (1 MHz) clock rates. Its internal architecture includes a 64-byte page buffer, dual-address-space pointer (shared between EEPROM array and OTP registers), and voltage-inhibited reset logic releasing at V_VCCI ≥ 1.55 V.

CBRAM® technology enables true byte-level write without read-modify-write overhead: each byte is written independently, delivering consistent 100,000-cycle endurance across –40°C to +85°C and eliminating degradation seen in floating-gate EEPROMs during byte-write operation. The OTP Security Register uses identical control protocol (Control Code "1011") but masks upper address bits to restrict access to 128 bytes.

Key Specifications

Pinout & Package

RM24C256DS-LMAI-T is packaged in an 8-lead SOIC (Small Outline Integrated Circuit) with standard JEDEC MS-012AC footprint (5.3 mm × 5.3 mm, 1.27 mm pitch). Pin functions are electrically validated per Adesto DS-RM24C256DS–085B.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C256C-SSHL-T and BR24G256FJ-WE2, RM24C256DS-LMAI-T uniquely combines 1 MHz I²C, CBRAM endurance stability across temperature, and integrated 128-byte OTP - enabling secure, low-power, long-life configuration storage without supplemental components.

Availability

RM24C256DS-LMAI-T is available at Aetrix Electronics and suitable for industrial sensor calibration, secure boot key storage, energy-harvesting node configuration, and automotive body control module NVM requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for RM24C256DS-LMAI-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

Adesto Technologies (acquired by Dialog Semiconductor in 2020, now part of Renesas Electronics) specialized in low-power, high-endurance non-volatile memory solutions based on proprietary CBRAM® technology.

The RM24C256DS product line was designed for embedded systems demanding secure, ultra-low-energy, temperature-resilient configuration storage - targeting industrial IoT, medical devices, and automotive subsystems where legacy EEPROM limitations impede reliability or power budgets.

FAQ

What is the maximum I²C clock frequency supported by RM24C256DS-LMAI-T?

The RM24C256DS-LMAI-T supports I²C clock frequencies up to 1 MHz under all operating conditions (1.65 V to 3.6 V, –40°C to +85°C). This is validated per AC specifications in DS-RM24C256DS–085B, with tSCLH ≥ 500 ns and CL ≤ 100 pF. At 1 MHz, RM24C256DS-LMAI-T achieves full throughput for page writes without timing margin violations.

How does the WP pin function on RM24C256DS-LMAI-T?

The WP (Write Protect) pin on RM24C256DS-LMAI-T is sampled only at the STOP condition of each write command. When pulled high (to VCC), it inhibits all write operations to the main memory array and OTP Security Register - reads remain fully functional. Pulling WP low enables writes. This edge-triggered sampling prevents spurious writes during power transitions or noise events.

Does RM24C256DS-LMAI-T include factory-programmed identification data?

Yes, RM24C256DS-LMAI-T includes a 128-byte OTP Security Register, of which the first 64 bytes are factory-programmed by Adesto with a unique identifier (UID). This UID is laser-trimmed and cannot be altered. The remaining 64 bytes are user-programmable once, making RM24C256DS-LMAI-T suitable for secure device binding and cryptographic key storage.

What is the endurance specification for RM24C256DS-LMAI-T across temperature?

RM24C256DS-LMAI-T guarantees 100,000 write cycles for both byte and page operations across its full operating temperature range (–40°C to +85°C), with no derating. Unlike floating-gate EEPROMs, CBRAM® technology delivers consistent endurance because each byte is written independently - eliminating the endurance penalty associated with partial-page updates.

Can RM24C256DS-LMAI-T operate from a 1.8 V supply?

Yes, RM24C256DS-LMAI-T operates reliably from 1.65 V to 3.6 V, making it compatible with 1.8 V systems without level shifting. At 1.8 V, it maintains full 1 MHz I²C capability, 64-byte page writes in ≤1.5 ms, and 50 nJ byte write energy. DC characteristics including ICC1 (0.25 mA active read current) and ICC3 (1.0 µA standby) are specified down to 1.65 V.