Renesas RM25C64C-BTAC-B

Overview

RM25C64C-BTAC-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 ultra-low-power IoT sensor nodes and battery-backed industrial controllers.

For engineers reviewing the RM25C64C-BTAC-B datasheet, RM25C64C-BTAC-B pinout, RM25C64C-BTAC-B application, or RM25C64C-BTAC-B equivalent, key selection criteria include its 2.2 µA power-down current, 100,000 write endurance, 10-year data retention, hardware/software write protection via WP pin and Status Register bits (SRWD, BP0/BP1), and dual low-power modes (Power Down and Ultra-Deep Power Down).

Technical Context

This device implements a 4-wire SPI interface (CS, SDO, SDI, SCK) with HOLD and WP control lines, enabling seamless integration into microcontroller-based systems requiring deterministic non-volatile storage. Its CBRAM® core eliminates charge-pump circuitry, enabling true single-supply operation and eliminating high-voltage programming requirements.

Internal architecture includes a 32-byte page buffer, status register with WIP/WEL flags, and configurable protection modes (block, status register, hardware via WP). Timing-critical operations - including fast read (10 MHz), byte write (25 µs), and page erase - are fully self-timed with no external wait-state management needed.

Key Specifications

Pinout & Package

RM25C64C-BTAC-B is housed in an 8-lead SOIC package (3.9 mm × 4.9 mm, 1.27 mm pitch), RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25DF041A-SSHN-B and M95M02-DRMN6TP, RM25C64C-BTAC-B uniquely delivers sub-2 µA power-down current, 1.65V operation, and 50 nJ byte-write energy - making it the only option for long-life, single-cell battery or energy-harvesting applications requiring true low-voltage EEPROM functionality.

Availability

RM25C64C-BTAC-B is available at Aetrix Electronics and suitable for smart meter firmware storage, medical sensor calibration data, industrial PLC configuration memory, wireless edge node state backup, and battery-backed real-time clock backup requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for RM25C64C-BTAC-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 using proprietary CBRAM® technology.

The RM25C-Series was designed specifically for energy-constrained, battery-operated IoT endpoints and industrial sensors requiring reliable, low-voltage, high-endurance serial memory with minimal system-level power overhead.

FAQ

What is the minimum supply voltage required for reliable operation of the RM25C64C-BTAC-B?

The RM25C64C-BTAC-B operates reliably down to 1.65V across its full temperature range (-40°C to +85°C). Below this threshold, the VVccI parameter (1.55V) triggers automatic inhibition of all write/erase commands - ensuring data integrity even during brown-out conditions. This makes RM25C64C-BTAC-B suitable for direct connection to 1.8V LDO outputs or partially discharged lithium coin cells.

How does the RM25C64C-BTAC-B implement write protection, and can it be configured per memory block?

The RM25C64C-BTAC-B supports both hardware and software write protection. Hardware protection uses the WP pin in conjunction with the SRWD bit in the Status Register to lock the Status Register itself. Software protection uses BP0/BP1 bits to define protected memory regions - including top ¼ (4 KB), top ½ (8 KB), or full array (64 Kbit). These settings are non-volatile and persist through power cycles.

What is the actual page size and maximum write speed for the RM25C64C-BTAC-B?

The RM25C64C-BTAC-B has a fixed 32-byte page size, and a typical page write time of 1 ms (max 5 ms). This is 4–6× faster than conventional EEPROMs of similar density. The device also supports single-byte writes completing in 25 µs (max 100 µs), enabled by its CBRAM® technology's direct-write mechanism without charge-pump delays.

Does the RM25C64C-BTAC-B support both SPI Mode 0 and Mode 3, and how does that affect MCU compatibility?

Yes, RM25C64C-BTAC-B explicitly supports SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1). This dual-mode support ensures interoperability with virtually all microcontrollers - including ARM Cortex-M, RISC-V, and legacy 8-bit MCUs - without requiring custom SPI peripheral configuration or bit-banging workarounds.

What are the power consumption differences between Standby, Power Down, and Ultra-Deep Power Down modes on the RM25C64C-BTAC-B?

In Standby mode (CS high), RM25C64C-BTAC-B draws 80–120 µA depending on temperature. In Power Down mode (PD command), current drops to 2.2–17 µA. In Ultra-Deep Power Down (UDPD command), it further reduces to 1.6–17 µA - the lowest among serial EEPROM alternatives. All modes retain memory contents and resume instantly upon wake-up command.