EEPROM Non-Volatile Storage Media Provides Robustness and Reliability
Grade 0 Realized with Enhanced Performance Including Write Cycles and Data Retention Period Compared to Grade 1 Version

In the automotive industry, safety is paramount, and safety standards become increasingly stringent over time. Features such as Electronic Stability Control (ESC) and Tire Pressure Monitoring Systems, which were once optional add-ons or limited to premium vehicles, have now become mandatory in nearly all vehicles.

For automotive ICs, there is a growing trend in demands for reliability and robustness. The automotive environment is one of the most challenging for ICs, as it is not only noisy but also subject to a wide range of temperatures. Even in applications with less temperature variation, such as steering, OEM companies demand high-reliability and high-durability components certified by AEC.

Non-volatile storage media such as EEPROM offers two key advantages. It operates properly even under stress environments and retains data even when the system is powered down. While other ICs experience stress only during operation, EEPROMs for data retention are constantly in use. Due to these characteristics, they are ideal for applications where robustness and reliability are critical, such as engine control, transmission electronics, steering, braking, and airbag systems.



Previously, the standard automotive grade for EEPROM was required to comply with AECQ-100 Grade 1, which specified a temperature range from -40°C to +125°C. With expanding electrical usage in vehicles and increasingly stringent safety standards, OnSemi has introduced an EEPROM product family compliant with AECQ-1000 Grade 0, which covers a temperature range from -40°C to +150°C. These products are serial EEPROMs with densities ranging from 1kb to 64kb, available in SOIC and TSSOP 8-pin packages. These devices communicate via the SPI protocol, a high-speed protocol that is the standard for both previous and current microcontrollers.

These devices demonstrate overall performance improvements compared to Grade 1 versions. Durability is enhanced with a higher temperature range, 4 million write cycles (compared to just 1 million in previous products), and a 200-year data retention period (compared to just 100 years previously). The minimum supply voltage is 1.7V at temperatures up to +125°C and 2.5V across the full voltage range.
Error Code Correction is implemented in hardware for each 8-bit word.

When a user writes byte data, the device automatically stores a code that represents this data as 3 redundant bits. If a single bit in the byte data becomes corrupted, the device detects this when the data is read again by checking against the extra redundant bits. It then automatically corrects the error before conveying it to the user. This process is transparent to the user, just like reading and writing memory in a standard serial EEPROM.