Renesas R1EX24064ASAS0A#S0

Overview

R1EX24064ASAS0A from Renesas Electronics is a 64-kbit (8,192 × 8-bit) two-wire serial EEPROM with I²C interface, 1.8–5.5 V single-supply operation, 400 kHz clock frequency, and SOP-8 package. It delivers high reliability via MONOS memory technology, supports 32-byte page writes, and is rated for −40°C to +85°C industrial temperature range - used in system configuration storage for embedded controllers and consumer electronics.

For engineers reviewing the R1EX24064ASAS0A datasheet, R1EX24064ASAS0A pinout, R1EX24064ASAS0A application, or R1EX24064ASAS0A equivalent, key selection criteria include its 5 ms write cycle time, 1,000k endurance cycles at 25°C, 100-year data retention, WP-enabled hardware write protection, and compatibility with standard I²C bus timing requirements.

Technical Context

This device implements a two-wire I²C-compatible serial interface with fixed 1010 device code, 3-bit hardware addressable A0–A2 pins enabling up to eight devices on one bus, and open-drain SDA/SCL requiring external pull-ups. The internal address counter supports current-address, random, and sequential read modes.

Write operations are controlled by the WP pin: low enables full-memory writes (byte or 32-byte page), high disables all writes and forces NACK after address receipt. Acknowledge polling is supported to detect write-cycle completion without fixed delay timing.

Key Specifications

Pinout & Package

Package: 150-mil 8-pin plastic SOP (PRSP0008DF-B / FP-8DBV), lead-free, surface-mount.

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-3GE2, the R1EX24064ASAS0A provides superior long-term data integrity (100-year retention) and failsafe hardware write protection - critical for industrial and infrastructure applications where field data corruption is unacceptable.

Availability

R1EX24064ASAS0A is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, consumer audio devices, and embedded sensor nodes requiring stable component supply across multi-year production cycles.

Supply support for R1EX24064ASAS0A 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

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and consumer markets.

The R1EX24xxx series was designed specifically for reliable, low-power nonvolatile storage in space- and power-constrained embedded systems - emphasizing robustness, wide voltage operation, and I²C interoperability.

FAQ

What is the maximum I²C clock frequency supported by the R1EX24064ASAS0A?

The R1EX24064ASAS0A supports a maximum I²C clock frequency of 400 kHz, compliant with Fast-mode I²C specifications. This allows typical read/write transactions to complete within tens to hundreds of microseconds depending on byte count and ACK timing. Exceeding 400 kHz may result in timing violations and unreliable communication - the device does not support 1 MHz High-speed mode.

Does the R1EX24064ASAS0A require external pull-up resistors on SDA and SCL lines?

Yes, the R1EX24064ASAS0A requires external pull-up resistors on both SDA and SCL lines because these pins use open-drain output structures. The recommended value depends on bus capacitance and desired rise time; typical values range from 2.2 kΩ to 10 kΩ for 3.3 V systems. Failure to install pull-ups will prevent proper I²C signal levels and cause communication failure.

How does the write protect (WP) pin function on the R1EX24064ASAS0A?

When the WP pin is driven high (VIH ≥ 0.7 × VCC), the R1EX24064ASAS0A disables all write operations - byte and page writes are rejected, and the device responds with NACK after receiving the memory address. When WP is low or floating (internally pulled down), full read/write access is enabled. This hardware lock operates independently of software state, providing fail-safe protection against unintended writes.

What is the endurance rating of the R1EX24064ASAS0A, and how is it affected by temperature?

The R1EX24064ASAS0A guarantees 1,000,000 write/erase cycles at 25°C and 100,000 cycles at 85°C. Endurance degrades with increasing junction temperature due to accelerated charge trapping in the MONOS structure. For applications operating continuously above 65°C, derating curves in the datasheet (REJ03C0332-0200) should be consulted to determine usable cycle count before end-of-life.

Can the R1EX24064ASAS0A be used in automotive applications?

The R1EX24064ASAS0A is classified as a "Standard" quality grade device per Renesas documentation and is intended for consumer and industrial applications such as meters, audio equipment, and embedded controllers. It is not qualified for automotive use (AEC-Q100), nor approved for safety-critical or under-hood environments. For automotive applications, Renesas recommends contacting their sales office for qualified alternatives.