STMicroelectronics STM32L4S9AII6

Overview

STM32L4S9AII6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, 120 MHz max frequency, 2 MB Flash, 640 KB SRAM, and integrated MIPI DSI host controller + LCD-TFT controller. It delivers 150 DMIPS and supports advanced graphics acceleration via Chrom-ART (DMA2D) and Chrom-GRC (GFXMMU), targeting high-resolution embedded displays in battery-constrained industrial HMIs and portable medical devices.

For engineers reviewing the STM32L4S9AII6 datasheet, STM32L4S9AII6 pinout, STM32L4S9AII6 application, or STM32L4S9AII6 equivalent, key selection criteria include its dual-bank read-while-write Flash architecture, 420 nA Standby-with-RTC power profile, 12-bit 5 Msps ADC with hardware oversampling, AES-256/HASH-256 crypto acceleration, and UFBGA169 package compatibility with MIPI D-PHY compliant display interfaces.

Technical Context

The STM32L4S9AII6 implements an adaptive real-time memory accelerator (ART Accelerator) enabling zero-wait-state execution from Flash at 120 MHz, paired with a multi-AHB interconnect matrix for concurrent peripheral access. Its FlexPowerControl architecture supports seven low-power modes-including 33 nA Shutdown and 420 nA Standby with RTC-managed by a dedicated power control block with brownout reset across all active modes except Shutdown.

Graphics subsystem integration includes a MIPI DSI Host controller with two lanes operating up to 500 Mbit/s each, coupled with an LCD-TFT controller (LTDC) supporting RGB888 and YUV formats, and hardware-accelerated DMA2D for 2D composition. The analog domain features dual 12-bit DACs, two rail-to-rail op-amps with programmable gain, and two ultra-low-power comparators-all supplied independently for noise isolation.

Key Specifications

Pinout & Package

STM32L4S9AII6 is housed in a 169-ball Ultra-Fine Pitch Ball Grid Array (UFBGA169) package with 0.4 mm ball pitch and 7 mm × 7 mm body size, optimized for high-density PCB layouts and thermal performance in compact industrial and portable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power MCU applications.

Compared with STM32L4R9AII6, the STM32L4S9AII6 provides integrated LCD-TFT and MIPI DSI for self-contained display systems, while STM32U585AII6 trades display features for hardened security and deeper low-power states-making the L4S9 optimal for cost-sensitive, graphics-rich edge HMIs without external security co-processors.

Availability

STM32L4S9AII6 is available at Aetrix Electronics and suitable for industrial HMI development, portable medical instrumentation, smart energy metering, and secure IoT gateway design requiring stable component supply and long-term lifecycle assurance.

Supply support for STM32L4S9AII6 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 analog components for industrial, automotive, and consumer markets.

The STM32L4 series targets ultra-low-power embedded applications demanding high performance per microwatt, with the L4S9 variant specifically engineered for graphics-intensive, battery-operated HMIs requiring integrated display controllers and cryptographic acceleration.

FAQ

What is the maximum operating temperature range for STM32L4S9AII6?

The STM32L4S9AII6 is qualified for industrial and extended temperature operation from –40 °C to +125 °C, verified per JEDEC JESD22-A108 and supported by thermal characterization data in DS12024 Rev 4 Section 7.7. This rating applies to the UFBGA169 package under specified PCB copper area and airflow conditions.

Does STM32L4S9AII6 support hardware JPEG encoding/decoding?

No, the STM32L4S9AII6 does not include dedicated JPEG codec hardware. Its graphics acceleration is limited to Chrom-ART (DMA2D) for 2D composition, Chrom-GRC for memory optimization, and LTDC for display timing generation. JPEG processing must be implemented in firmware using CPU or external co-processor.

Can the MIPI DSI interface drive a 1080p display?

Yes-the MIPI DSI Host supports two lanes at up to 500 Mbit/s each (1 Gbit/s aggregate), sufficient for 1080p@60 Hz with RGB888 and 24-bit color depth using LP/HS mode transitions. Actual resolution support depends on display panel timing constraints and LTDC configuration, validated in ST application note AN5023.

Is the 2 MB Flash memory organized as a single bank or dual banks?

The 2 MB Flash is physically divided into two independent banks (Bank 1 and Bank 2), enabling true read-while-write operation: one bank can execute code while the other is being erased or programmed. This architecture is confirmed in Section 3.4 of DS12024 Rev 4 and required for safe firmware updates in field-deployed devices.