STMicroelectronics STM8AF6246UDX

Overview

STM8AF6246UDX from STMicroelectronics is an AEC-Q100 qualified automotive 8-bit microcontroller featuring a 16 MHz STM8A core, 16 Kbyte Flash program memory, 1 Kbyte true data EEPROM, and integrated LINUART, SPI, I²C, 10-bit ADC, and advanced timers. It operates from 3 to 5.5 V and supports ambient temperatures up to 150 °C, targeting engine control units and body electronics modules.

For engineers reviewing the STM8AF6246UDX datasheet, STM8AF6246UDX pinout, STM8AF6246UDX application, or STM8AF6246UDX equivalent, key selection criteria include AEC-Q100 Grade 0 qualification, VFQFPN32 (5×5 mm) package compatibility, LIN 2.2 master/slave support, 10-bit ADC with scan mode, and 2 Kbyte RAM for real-time automotive firmware execution.

Technical Context

The STM8AF6246UDX implements a Harvard-architecture STM8A CPU with 3-stage pipeline and average 1.6 cycles/instruction throughput, delivering 10 MIPS at 16 MHz. Its clock system integrates user-trimmable 16 MHz HSI and 128 kHz LSI oscillators plus external crystal support, all monitored by a dedicated clock security system (CSS).

Interrupt handling uses a nested controller with 32 vectors and up to 34 external interrupt sources mapped across five priority levels. Memory subsystem includes Flash with 20-year data retention at 55 °C after 1 kcycle and EEPROM rated for 300 kwrite cycles, both protected by configurable read-out and write protection mechanisms.

Key Specifications

Pinout & Package

STM8AF6246UDX is housed in a 32-pin VFQFPN (Very Thin Profile Fine Pitch Quad Flat Package) with 5 × 5 mm body and 0.5 mm lead pitch. The package supports reflow soldering and provides thermal performance suitable for high-temperature automotive environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM8AF6266UDX, the STM8AF6246UDX trades Flash/RAM headroom for lower cost and smaller code footprint; versus RL78/F13-BCG, it delivers integrated LIN and higher temperature rating at the expense of vendor-specific toolchain lock-in.

Availability

STM8AF6246UDX 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 lifecycles.

Supply support for STM8AF6246UDX 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 devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

The STM8A automotive microcontroller product line targets cost-sensitive, high-reliability embedded control applications requiring AEC-Q100 qualification, extended temperature operation, and integrated communication peripherals for vehicle subsystems.

FAQ

What is the maximum operating frequency and corresponding supply voltage range for the STM8AF6246UDX?

The STM8AF6246UDX achieves a maximum CPU frequency of 16 MHz across its full 3.0 V to 5.5 V supply range, as confirmed by Figure 8 (fCPUmax vs. VDD) in the datasheet. At 3.0 V, fCPUmax remains 16 MHz due to adaptive internal regulation, enabling consistent performance during cold-cranking conditions where battery voltage dips below 4 V.

Does the STM8AF6246UDX support hardware-based LIN bus communication without external transceivers?

Yes - the integrated LINUART peripheral complies fully with LIN 2.2 and supports both master and slave modes with automatic resynchronization. However, a physical-layer LIN transceiver (e.g., TLE7259-3GE) is still required for bus-level signal conditioning, ESD protection, and dominant/recessive voltage level translation per ISO 17987-4.

How is the 1 Kbyte data EEPROM organized and accessed in the STM8AF6246UDX?

The 1 Kbyte data EEPROM is implemented as a separate, wear-leveled memory block accessible via dedicated EEPROM programming instructions (WRTEE, RDEE). It supports byte/word writes and page erases, with each address having independent 300 kcycle endurance. Access is controlled through EEPRM_CR register bits and protected by option bytes to prevent accidental overwrite.

What low-power modes are available and what is the typical current consumption in Halt mode?

The STM8AF6246UDX offers Wait, Auto-wakeup, and Halt modes. In Halt mode with all clocks stopped except the independent watchdog (IWDG) and auto-wakeup timer (AWU), typical current consumption is 0.9 µA at 25 °C and 5.0 V (Table 24). With RTC enabled using LSI, consumption rises to ~2.5 µA - verified under TA = −40 to +55 °C conditions.