Renesas RM25C64C-LTAI-B

Overview

RM25C64C-LTAI-B from Adesto Technologies is a 64 Kbit non-volatile serial EEPROM memory IC based on CBRAM® resistive switching technology, operating from 1.65V to 3.6V supply, supporting SPI modes 0 and 3, with 10 MHz fast read capability and 32-byte page write in 1 ms - deployed in low-power IoT sensor nodes for firmware parameter storage.

For engineers reviewing the RM25C64C-LTAI-B datasheet, RM25C64C-LTAI-B pinout, RM25C64C-LTAI-B application, or RM25C64C-LTAI-B equivalent, key selection considerations include its ultra-low 2.2 µA power-down current, 100,000 write-cycle endurance, 10-year data retention, CBRAM-based energy efficiency (50 nJ/byte write), and SOIC-8/TSSOP-8 package compatibility.

Technical Context

The RM25C64C-LTAI-B implements a 4-wire SPI interface (CS, SDO, SDI, SCK) with dual read modes: normal (≤1.6 MHz) and fast (≤10 MHz). It uses self-timed internal erase/write cycles and supports byte-wise and 32-byte page programming with automatic address incrementing within pages.

Its CBRAM® memory array enables direct-write operation without charge pumps, delivering faster page writes (4–6× vs. conventional EEPROM) and lower energy per byte. Protection is implemented via hardware (WP pin + SRWD bit) and software (WEL latch, BP0/BP1 block protection, APDE/LPSE power modes).

Key Specifications

Pinout & Package

RM25C64C-LTAI-B is housed in an 8-lead SOIC package (5.3 mm × 4.4 mm, 1.27 mm pitch), RoHS-compliant and halogen-free, with standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSH-T and M95M04-DRMN6TP/K, RM25C64C-LTAI-B delivers superior energy efficiency per write operation, faster page programming, and native support for true byte-level updates - making it optimal for battery-constrained, high-write-frequency embedded systems where endurance and low quiescent current are design-critical.

Availability

RM25C64C-LTAI-B is available at Aetrix Electronics and suitable for industrial sensor nodes, medical wearables, smart metering systems, and automotive body control modules requiring stable component supply across long production lifecycles.

Supply support for RM25C64C-LTAI-B 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 ultra-low-power non-volatile memory solutions for resource-constrained IoT endpoints.

The RM25C-Series was designed specifically for energy-sensitive embedded applications requiring high endurance, fast write performance, and minimal active/standby current - leveraging CBRAM® to replace legacy EEPROM in next-generation sensor and wearable platforms.

FAQ

What is the maximum SPI clock frequency supported by RM25C64C-LTAI-B in fast read mode?

The RM25C64C-LTAI-B supports up to 10 MHz SCK frequency in fast read mode, enabling high-speed parameter retrieval. This is double the 1.6 MHz limit of normal read mode and requires CL = 10 pF loading. The device maintains valid timing margins (tOV = 6.5 ns, tSCKH/tSCKL = 7.5 ns) across the full -40°C to +85°C temperature range, ensuring reliable operation in thermally demanding environments. RM25C64C-LTAI-B must be configured for fast read using the 0BH opcode with a dummy byte.

How does the CBRAM® technology in RM25C64C-LTAI-B improve write energy efficiency compared to standard EEPROM?

RM25C64C-LTAI-B achieves 50 nJ per byte write energy - just 10% of typical EEPROM consumption - because its CBRAM® cell operates via low-current resistive switching without charge pumps or Fowler-Nordheim tunneling. This eliminates high-voltage generation overhead and reduces both dynamic power and thermal dissipation. In practice, RM25C64C-LTAI-B enables 10,000+ daily writes on a CR2032 coin cell for over 3 years, whereas equivalent EEPROMs would deplete the same battery in <1 year. The technology is intrinsic to RM25C64C-LTAI-B's architecture and requires no host-side firmware changes.

Can RM25C64C-LTAI-B be used in systems with a 1.8 V supply rail?

Yes, RM25C64C-LTAI-B is fully specified for operation from 1.65 V to 3.6 V, making it compatible with standard 1.8 V logic interfaces without level shifters. At 1.8 V, DC characteristics include ICC2 = 0.25 mA (typical read current), ICC5 = 2.2 µA (power-down current), and VIH = 1.26 V (70% of VCC). All AC timing parameters (including 10 MHz fast read) remain valid down to 1.65 V, and the device guarantees full functionality across the entire industrial temperature range (-40°C to +85°C) at 1.8 V. RM25C64C-LTAI-B's low VCCmin eliminates need for auxiliary voltage regulation in 1.8 V SoC designs.

What protection mechanisms prevent accidental writes to RM25C64C-LTAI-B during power-up or brown-out conditions?

RM25C64C-LTAI-B incorporates three layered protections: (1) VCC inhibit threshold (VVccI = 1.55 V) blocks all commands below this voltage; (2) Write Enable Latch (WEL) resets automatically after each non-read instruction and must be set via WREN before every write/erase; (3) Hardware write protect via WP pin, which locks the Status Register when SRWD = 1. These features ensure RM25C64C-LTAI-B remains immune to spurious writes during power ramp-up, dropout, or noise events - critical for fail-safe operation in medical and industrial systems.

Does RM25C64C-LTAI-B support page erase, and how is it initiated?

Yes, RM25C64C-LTAI-B supports 32-byte page erase using the PERS (0x42) instruction. After issuing WREN to set the Write Enable Latch, the host sends the 0x42 opcode followed by any 2-byte address within the target page (bits A5–A0 are ignored). Bringing CS high initiates the self-timed erase; completion is signaled by WIP = 0 in the Status Register. Page erase sets all bits in the 32-byte block to '1', enabling selective reprogramming without chip-wide erasure. This capability is integral to RM25C64C-LTAI-B's firmware update architecture and is validated for 100,000 cycles.