Renesas R1EX24128BSAS0I#U0

Overview

R1EX24128BSAS0I from Renesas Electronics is a 128-kbit (16,384 × 8-bit) two-wire serial EEPROM with I²C interface, MONOS memory technology, and SOP-8 package. It operates from 1.8 V to 5.5 V, supports 400 kHz clock frequency, delivers 5 ms write cycle time, and guarantees 1,000k write endurance and 100-year data retention - deployed in industrial control modules for parameter storage and calibration data backup.

For engineers reviewing the R1EX24128BSAS0I datasheet, R1EX24128BSAS0I pinout, R1EX24128BSAS0I application, or R1EX24128BSAS0I equivalent, key selection criteria include its halogen-free #U0 marking, 64-byte page write capability, −40°C to +85°C operating range, WP pin-based hardware write protection, and compatibility with standard I²C bus timing requirements.

Technical Context

This EEPROM implements a two-wire I²C-compatible serial interface with fixed device code "1010", supporting up to eight devices on one bus via A0–A2 address pins. Its internal architecture includes a high-voltage generator, address decoder, and serial-parallel converter, enabling byte and page write operations without external high-voltage programming circuitry.

It features automatic page write (64-byte/page), acknowledge polling for write-cycle status detection, and built-in power-on reset to prevent unintended writes during VCC ramp-up. The device uses MONOS nonvolatile memory cells fabricated on a CMOS process, delivering low active current (1.0 mA max read, 3.0 mA max write) and ultra-low standby current (2.0 μA max at 5.5 V).

Key Specifications

Pinout & Package

Package: 150-mil 8-pin plastic SOP (PRSP0008DF-B / FP-8DBV), lead-free and halogen-free (#U0).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C128B-PU and M95128-DRMN6TP/K, the R1EX24128BSAS0I offers halogen-free construction, guaranteed −40°C to +85°C operation, and MONOS-based robustness for mission-critical industrial use - making it preferable where long-term reliability and environmental compliance are mandatory.

Availability

R1EX24128BSAS0I is available at Aetrix Electronics and suitable for industrial control systems, smart sensor nodes, medical diagnostics equipment, and point-of-sale terminals requiring stable component supply across multi-year production cycles.

Supply support for R1EX24128BSAS0I 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 is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and infrastructure markets.

The R1EX24xxx series was designed specifically for high-reliability, low-power nonvolatile storage in space-constrained industrial and medical devices - emphasizing halogen-free packaging, extended temperature operation, and MONOS cell longevity.

FAQ

What is the maximum I²C clock frequency supported by the R1EX24128BSAS0I?

The R1EX24128BSAS0I supports a maximum I²C clock frequency of 400 kHz, compliant with standard-mode I²C specifications. This allows reliable communication with most microcontrollers while maintaining noise immunity and signal integrity on typical PCB traces. The device's AC characteristics specify tLOW ≥ 1200 ns and tHIGH ≥ 600 ns to ensure proper timing margin at this rate.

Does the R1EX24128BSAS0I require an external high-voltage programming supply?

No, the R1EX24128BSAS0I does not require an external high-voltage programming supply. It uses MONOS memory technology with integrated high-voltage generation, enabling full 1.8–5.5 V single-supply operation. All write and erase functions are performed using only the VCC rail - simplifying power design and eliminating external charge pumps or programming voltages.

How does the WP pin function on the R1EX24128BSAS0I?

On the R1EX24128BSAS0I, the WP (Write Protect) pin is an active-high input that disables all write operations across the entire 128 kbit memory array when driven high. When WP = VIH, the device returns a NO ACK ('1') after receiving write data, preventing modification. WP must not float - it requires explicit connection to VCC or VSS per datasheet guidance.

What is the page write size and write cycle time for the R1EX24128BSAS0I?

The R1EX24128BSAS0I supports 64-byte page writes, and its maximum write cycle time is 5 ms per page. This means up to 64 bytes can be written in a single atomic operation, significantly reducing host processor overhead compared to byte-wise writes. The 5 ms duration is internally controlled and begins after the STOP condition is detected.

Is the R1EX24128BSAS0I compatible with 1.8 V microcontrollers?

Yes, the R1EX24128BSAS0I is fully compatible with 1.8 V microcontrollers. Its supply voltage range is 1.8 V to 5.5 V, and its DC characteristics (VIH = 0.7 × VCC, VIL = 0.3 × VCC) ensure reliable logic-level recognition at 1.8 V. Input/output capacitance is specified at ≤6.0 pF, supporting clean signal transitions even with weak MCU drive strength.