company blog about Microchip AT25128 Automotive 128Kb SPI Serial EEPROM Memory

Shenzhen Mingjiada Electronics Co., Ltd. supplies the Microchip AT25128 automotive-grade 128Kb SPI serial EEPROM memory.

I. AT25128 Product Details

1. AT25128 Product Description

The AT25128 (AT25128A/AT25128B) is an AEC-Q100 automotive-grade SPI interface serial EEPROM launched by Microchip, with a storage capacity of 128Kbit and a 16384×8bit architecture. Designed specifically for automotive electronics and high-reliability industrial control applications, it supports low-voltage operation and high-speed SPI communication. Featuring a comprehensive data write protection mechanism, it is suitable for the long-term storage of non-volatile information such as configuration parameters, calibration data, device serial numbers and fault logs, and meets the persistent storage requirements of systems such as in-vehicle main control units, sensor modules and body control units. The device is compatible with SPI Mode 0 (0,0) and Mode 3 (1,1), allowing direct interfacing with mainstream in-vehicle MCUs. It requires few pin resources, facilitating a compact PCB layout.

2. AT25128 Key Specifications

- Storage capacity: 128Kb (16K × 8-bit)

- Communication interface: SPI serial bus, maximum clock speed 20MHz

- Supply voltage: 1.8V–5.5V wide voltage range, compatible with various automotive power rails

- Operating temperature: Automotive-grade version –40°C to +125°C, meeting AEC-Q100 automotive certification requirements

- Erase/write endurance: Up to 1,000,000 erase/write cycles per memory cell

- Data retention: Non-volatile data retention for over 200 years

- Page write operations: Supports page writing, with 32 bytes per page; typical page write time is 5 ms

- Package options: Various packages including 8-pin SOIC, TSSOP, UDFN and PDIP

- Compliance: AEC-Q100 automotive-grade certification; supports PPAP documentation; RoHS-compliant packaging

3. AT25128 Product Features

1. Automotive-grade high reliability; AEC-Q100 certified; withstands extreme temperatures, vibration and electromagnetic interference in automotive environments

2. Supports block-based write protection, with configurable protection for 1/4, 1/2 or the entire memory array to prevent accidental erasure of critical calibration data

3. Built-in power-on/power-off protection circuits, a write-enable latch and an independent WP (Write Protect) pin provide multiple layers of protection against unauthorised data overwriting

4. Supports continuous sequential reading, enhancing the efficiency of batch log and parameter retrieval

5. Low static power consumption and low standby current, suitable for in-vehicle battery power supply and low-power sensor nodes

6. Clock supports SPI Mode 0 and Mode 3, offering strong compatibility with mainstream in-vehicle MCUs

7. Compact surface-mount package, suitable for high-density in-vehicle PCB design, and supports mass production SMT placement via tape-and-reel packaging

4. Typical Applications of the AT25128

Primarily targeted at automotive electronics, whilst also covering high-reliability industrial scenarios:

- Automotive ADAS perception modules: storage of calibration parameters and calibration coefficients for cameras and millimetre-wave radars

- Body domain controllers and BCM (Body Control Module): configuration parameters for seats, lights and windows

- Powertrain and Battery Management Systems (BMS): fault codes, SOC calibration, production serial numbers, traceability information

- In-vehicle gateways and infotainment peripherals: user configurations, version information, security key backups

- Industrial automation and humanoid robot controllers: sensor calibration parameters, device identification information

- Drones and smart gateways: operational logs, hardware calibration data storage

II. Procurement, Product Selection and Buyer’s Guide

Key Considerations for Product Selection

1. Model suffixes indicate grade: Prioritise versions with automotive-grade suffixes (e.g. AT25128B automotive-grade model) and confirm AEC-Q100 compliance; industrial-grade versions must not be used as substitutes for automotive applications. Suffixes also indicate package type, packaging format (tape and reel / tube) and temperature grade.

2. Package Selection: For mass production, prioritise SOIC and UDFN surface-mount packages; for sample debugging, PDIP through-hole packages may be used; for high-density circuit boards, prioritise the 2×3 mm UDFN package.

3. Voltage Range Verification: For 3.3 V automotive systems, the 1.8–5.5 V version may be used directly without the need for additional level conversion.

4. Documentation Requirements: For automotive projects, it is necessary to confirm in advance whether PPAP, material certificates, batch test reports or traceable batch numbers are required; Mingjiada can provide original manufacturer documentation as required.

5. Substitution precautions: Do not confuse this with the 25LC128 or 25AA128. Whilst all three are 128Kb SPI EEPROMs, they differ in certification grade, temperature range and reliability parameters; they are not directly interchangeable in automotive projects.

Procurement risk warnings

- Automotive-grade components have strict requirements regarding batches and traceability; it is not recommended to purchase loose components without batch numbers or original manufacturer labels to avoid the risks associated with refurbished or salvaged parts.

- Calculate erase/write cycles in advance: EEPROMs have a maximum erase/write limit of one million cycles; write-equalisation algorithms must be designed for high-frequency real-time writing scenarios.

- Lead time planning: Lead times for automotive-grade components from original manufacturers are typically lengthy; for mass production projects, it is advisable to secure stock in advance and maintain a safety stock buffer.

Recommendations for Sample and Bulk Procurement

During the R&D phase, samples may be requested for hardware debugging and high/low-temperature reliability testing; small-batch trial production should be conducted to verify batch documentation; mass production orders should be secured through long-term supply plans to ensure continuous project delivery.

III. Mingjiada Electronics’ Electronic Component Supply Process

Shenzhen Mingjiada Electronics specialises in the distribution of genuine, original electronic components, covering a wide range of brands. We support the supply of high-reliability components—including automotive-grade, industrial-grade and telecommunications-grade parts—from stock, as well as the procurement of hard-to-source items. We also provide a dead stock recovery service. The standardised procurement process is as follows:

1. Submission of Requirements

Customers submit their requirements via the official website, telephone, email or through their account manager, specifying the full part number, package type, quantity, automotive-grade certification requirements, target delivery date, and whether the order is for a sample, trial production or mass production.

2. Stock and Quotation Confirmation

The sales team swiftly verifies stock availability and the original manufacturer’s production schedule, providing a quotation, lead time and packaging details within one hour. They simultaneously verify whether the component specifications and automotive-grade certifications match the customer’s project requirements, whilst the technical team is available to assist with parameter enquiries and component selection reviews.

3. Signing of Commercial Agreement

Both parties confirm the price and delivery terms before signing the purchase contract; For automotive projects, an NDA (Non-Disclosure Agreement) may be signed concurrently, stipulating quality responsibilities, traceability requirements and a list of documents to be provided; various payment methods are supported.

4. Incoming Goods Inspection and Documentation

Incoming materials undergo visual inspection, batch number and label verification, whilst automotive-grade batches are cross-checked against the manufacturer’s certificates; shipments are accompanied by the manufacturer’s material reports and batch traceability documentation, with PPAP documents provided upon request.

5. Logistics, Delivery and Order Tracking

Air or land transport is selected according to customer requirements; we support domestic delivery and cross-border DDP customs clearance services, with full order traceability throughout the process; reel-and-tape materials are packaged with anti-static protection to prevent electrostatic damage to EEPROM memory chips.

6. After-Sales Technical Support and Delivery Assurance

We assist customers with re-inspection upon receipt of goods; in the event of queries regarding specifications or batches, we liaise swiftly with the original manufacturer for verification; for long-term mass-production customers, we offer safety stock management services, whilst also undertaking the recycling of idle memory chips from the same series as part of customer projects.