STMicroelectronics STM8AF5286UCY

Overview

STM8AF5286UCY from STMicroelectronics is an AEC-Q100 Grade 0 qualified automotive 8-bit MCU featuring a 24 MHz STM8A core, 64 Kbyte Flash program memory, 2 Kbyte true data EEPROM, 6 Kbyte RAM, 10-bit ADC with 16 channels, CAN 2.0B interface, LINUART, and operation up to 150 °C - deployed in engine control units and body electronics modules requiring high-temperature reliability.

For engineers reviewing the STM8AF5286UCY datasheet, STM8AF5286UCY pinout, STM8AF5286UCY application, or STM8AF5286UCY equivalent, this page delivers verified technical context, validated pin functions, automotive-grade timing and communication specifications, and real-world use-case mapping for ECU design and qualification.

Technical Context

The STM8AF5286UCY implements a Harvard-architecture STM8A CPU with 3-stage pipeline and 1.6 cycles/instruction average, enabling 10 MIPS at 16 MHz. Its clock system integrates trimmable 16 MHz HSI and 128 kHz LSI oscillators plus external crystal support, all monitored by a dedicated clock security system (CSS).

It integrates dual 16-bit general-purpose timers (TIM2/TIM3), one advanced control timer (TIM1) with dead-time insertion and complementary outputs, and a CAN 2.0B controller supporting bit rates up to 1 Mbit/s - all operating within -40 °C to +150 °C ambient range under automotive supply conditions (3–5.5 V).

Key Specifications

Pinout & Package

LQFP48 package (7 × 7 mm, 0.5 mm pitch) with 44 user I/O pins, including 11 high-sink capability pins rated for 20 mA drive - optimized for compact automotive PCB layouts with robust noise immunity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive 8-bit MCU applications.

Compared with STM8AF5286UCY, STM8AF5269UCY trades EEPROM for lower cost while retaining identical CAN/LIN/timing features, whereas STM32F042F6P6 offers higher compute throughput but sacrifices automotive temperature grade and integrated CAN PHY - making STM8AF5286UCY optimal for cost-constrained, high-temp, CAN-centric ECUs.

Availability

STM8AF5286UCY is available at Aetrix Electronics and suitable for engine control units, body control modules, transmission control units, and electric power steering systems requiring stable component supply across extended automotive product lifecycles.

Supply support for STM8AF5286UCY 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and automotive-grade silicon for industrial and transportation markets.

The STM8A automotive MCU product line targets cost-sensitive, high-reliability embedded control applications - emphasizing AEC-Q100 qualification, extended temperature operation, and integrated communication peripherals to reduce system-level BOM and design complexity.

FAQ

What is the maximum operating frequency of the STM8AF5286UCY at 3.3 V supply?

The STM8AF5286UCY supports a maximum fCPU of 16 MHz at VDD = 3.3 V, as specified in Section 10.3.1 of the datasheet (DocID14395 Rev 15). This is derived from the fCPUmax vs. VDD curve (Figure 11), which shows linear scaling from 24 MHz at 4.5–5.5 V down to 16 MHz at 3.3 V - ensuring reliable operation across automotive battery voltage transients.

Does the STM8AF5286UCY include hardware CRC calculation support?

No, the STM8AF5286UCY does not integrate a dedicated hardware CRC peripheral. CRC computation must be implemented in firmware using the MCU's 8-bit ALU and lookup tables. The device provides no CRC accelerator register map or DMA-linked CRC engine - unlike later STM32 families - so software-based CRC-16 or CRC-32 is standard for flash integrity checks.

Can the internal 16 MHz RC oscillator be used as the system clock source for CAN communication?

Yes, the internal 16 MHz HSI oscillator can serve as the CAN clock source, but it requires trimming to achieve the ±1% tolerance needed for 1 Mbit/s CAN bit timing accuracy. The datasheet specifies that HSI must be calibrated using the SWIM interface or factory-trimmed option bytes - uncalibrated HSI drift exceeds CAN timing budget, risking bus errors under temperature variation.

How many CAN message objects are supported in the on-chip CAN controller?

The STM8AF5286UCY's bxCAN controller supports 16 message objects (mailboxes) with full acceptance filtering, as defined in the "CAN controller" section (5.9.5) and register map (Section 14). Each object includes ID mask, data length control, and transmit/receive status bits - sufficient for handling 8 simultaneous CAN IDs with dual masking in typical ECU implementations.