Renesas R1EX24128BTAS0A#U0

Overview

R1EX24128BTAS0A from Renesas Electronics is a 128-kbit (16,384 × 8-bit) two-wire serial EEPROM with I²C interface, 400 kHz clock support, 1.8–5.5 V supply range, and TSSOP-8 package. It delivers 5 ms write cycle time, 1,000k endurance cycles at 25°C, and 100-year data retention - deployed in consumer audio equipment, camcorders, and cellular phones for nonvolatile configuration storage.

For engineers reviewing the R1EX24128BTAS0A datasheet, R1EX24128BTAS0A pinout, R1EX24128BTAS0A application, or R1EX24128BTAS0A equivalent, key selection criteria include write-protect functionality, page-write capability (64-byte), low-power standby current (2 µA max), and industrial-grade temperature operation (−40 to +85°C).

Technical Context

This device implements a two-wire I²C-compatible serial interface with fixed 1010 device code and user-configurable A0–A2 address pins enabling up to eight devices on one bus. It uses MONOS memory technology for high reliability and low-voltage CMOS circuitry for operation down to 1.8 V.

Write protection is hardware-controlled via the WP pin: logic-high disables all writes across the full 128 kbit array, while logic-low enables byte and page write operations. Internal address auto-increment supports sequential read/write, and acknowledge polling allows host firmware to detect write completion without fixed delay timing.

Key Specifications

Pinout & Package

Package: 8-pin plastic TSSOP (PTSP0008JC-B / TTP-8DAV), 4.4 mm × 3.0 mm footprint, 0.65 mm pitch, lead-free, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C128C-SSHL-T and BR24G128FJ-WE2, the R1EX24128BTAS0A offers guaranteed 400 kHz timing compliance with relaxed slew-rate requirements, hardware-based WP for fail-safe protection, and MONOS-based reliability validated for consumer-grade longevity - making it optimal for cost-sensitive, layout-constrained designs where deterministic write timing and robustness outweigh raw speed.

Availability

R1EX24128BTAS0A is available at Aetrix Electronics and suitable for audio equipment, camcorders, and cellular phone peripherals requiring stable component supply, RoHS-compliant packaging, and long-lifecycle availability.

Supply support for R1EX24128BTAS0A 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 targets cost-sensitive, space-constrained consumer electronics needing reliable, low-voltage serial EEPROM - designed specifically for integration into camcorders, audio gear, and mobile accessories where write-protection and long-term data integrity are essential.

FAQ

What is the maximum I²C clock frequency supported by the R1EX24128BTAS0A?

The R1EX24128BTAS0A supports a maximum I²C clock frequency of 400 kHz, compliant with standard-mode I²C specifications. This is confirmed in the AC Characteristics table (Page 3 of datasheet R10DS0006EJ0100), where fSCL max = 400 kHz under −40 to +85°C and 1.8–5.5 V supply. Exceeding this frequency may cause timing violations and communication failure.

Does the R1EX24128BTAS0A require external pull-up resistors on SDA and SCL lines?

Yes, the R1EX24128BTAS0A requires external pull-up resistors on both SDA and SCL lines because its I/O structure is open-drain. The datasheet specifies that SDA must be pulled up to ensure proper logic levels and ACK/NACK signaling. Resistor value selection depends on bus capacitance, VOL, and IOL - typical values range from 2.2 kΩ to 10 kΩ for 400 kHz operation.

How does the Write Protect (WP) pin function on the R1EX24128BTAS0A?

When the WP pin is driven high (VIH ≥ 0.7 × VCC), the R1EX24128BTAS0A disables all write operations across its entire 128 kbit memory array and returns NACK after address transmission. When WP is low (VIL ≤ 0.3 × VCC), full read/write access is enabled. This hardware-level protection operates independently of I²C commands and remains active during power transitions.

What is the page write size and write cycle time for the R1EX24128BTAS0A?

The R1EX24128BTAS0A supports 64-byte page writes, and its write cycle time is 5 ms maximum per page - specified as tWC in the AC Characteristics table (Page 3). This applies to both byte and page writes; the 5 ms duration begins at the STOP condition and ends when the device re-enters standby mode and responds to new I²C commands.

Is the R1EX24128BTAS0A suitable for industrial temperature applications?

Yes, the R1EX24128BTAS0A is rated for operation from −40°C to +85°C, meeting industrial temperature grade requirements. This is explicitly stated in the "Features" section and confirmed in the "DC Operating Conditions" table (Page 2). It is authorized for industrial applications including meters and embedded controllers, subject to Renesas' quality grade classification and prior consultation per datasheet notice.