STM8AF5289TCY: 8-Bit Automotive MCU with 128KB Flash - XAIPART Summary

Originally reported by XAIPART on 2026-08-17

Key Points

• The STM8AF5289TCY is an 8-bit automotive MCU from STMicroelectronics with a 24 MHz STM8A core and 128 KB Flash memory.
• It integrates 6 KB RAM and 2 KB EEPROM with up to 300k write/erase cycles, operating from 3.0V to 5.5V.
• The device is AEC-Q100 qualified and operates over -40°C to +150°C, making it suitable for harsh automotive environments.
• It features a 12-bit ADC with 16 channels, multiple timers, and SPI, I2C, UART, and LIN interfaces.
• Available in an LQFP-64 package, it is priced at $2.8636 per unit at quantity 960 as of 2026-08-17.

Details

The STM8AF5289TCY from STMicroelectronics is an 8-bit automotive-grade microcontroller designed for real-time control in vehicles. Its high-performance STM8A core runs at up to 24 MHz, delivering up to 20 MIPS. The device includes 128 KB of Flash program memory with read-while-write capability, 6 KB of SRAM, and 2 KB of true EEPROM. The EEPROM supports up to 300,000 write/erase cycles, making it ideal for storing calibration data and fault codes.

The MCU operates over a supply voltage range of 3.0V to 5.5V, allowing direct connection to automotive battery systems via a regulator. It is AEC-Q100 qualified, ensuring reliability under extreme temperatures, humidity, and vibration. The operating temperature range spans -40°C to +150°C, covering under-hood and body applications.

Peripherals include two 16-bit timers, one 8-bit timer, and a 12-bit ADC with up to 16 channels. Communication interfaces include SPI, I2C, UART, and LIN, enabling connectivity with sensors, actuators, and other ECUs in vehicle networks. The device supports low-power modes (Wait, Active-Halt, Halt) to reduce current consumption when the vehicle is off.

Typical applications include automotive body control modules (BCM), motor control for pumps and fans, HVAC control, window lift and mirror control, and lighting control. The 128 KB Flash provides ample space for complex control algorithms, such as anti-pinch detection and field-oriented control (FOC) for BLDC motors.

For engineers, the STM8AF5289TCY offers a cost-effective alternative to 32-bit MCUs for tasks that do not require high computational power. Its robust feature set and automotive qualification make it a reliable choice for safety-critical systems. When designing, ensure proper decoupling of VDD and VDDA pins with 100nF capacitors, and connect a 100nF capacitor to the NRST pin for reliable reset.

Pricing as of 2026-08-17: $4.9091 (1+), $3.5455 (10+), $3.1364 (100+), $3.00 (500+), $2.8636 (960+). The device is in stock with 99,999 units available, and the MOQ is 1.

For engineers and procurement professionals, this MCU provides a balanced combination of memory, peripherals, and automotive-grade reliability, making it suitable for a wide range of vehicle control modules.

Read full article