STMicroelectronics STM32L412RBI6

Overview

STM32L412RBI6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 128 KB flash, 40 KB SRAM, and integrated analog peripherals including dual 12-bit ADCs (5 Msps), one operational amplifier with PGA, and one ultra-low-power comparator. It supports external SMPS for optimized efficiency and targets battery-powered IoT sensor nodes, portable medical devices, and energy-harvesting systems.

For engineers reviewing the STM32L412RBI6 datasheet, STM32L412RBI6 pinout, STM32L412RBI6 application, or STM32L412RBI6 equivalent, key selection criteria include its 28 µA/MHz run-mode current at 3.3 V with SMPS, 245 nA standby-with-RTC power, 4 µs wakeup from Stop mode, and LQFP64 (10×10 mm) package compatibility with industrial temperature range (–40 °C to +85 °C).

Technical Context

The device implements FlexPowerControl architecture with multiple low-power modes: Shutdown (16 nA), Standby (32 nA), Standby+RTC (245 nA), Stop 2 (0.7 µA), and Run mode down to 28 µA/MHz using external SMPS. Its ART Accelerator™ enables zero-wait-state execution from flash at 80 MHz, while the interconnect matrix decouples bus arbitration for deterministic peripheral access.

Clock system includes four independent sources: 4–48 MHz HSE, 32 kHz LSE for RTC, factory-trimmed 16 MHz HSI (±1%), and auto-calibrated MSI (±0.25% accuracy). USB 2.0 full-speed operates without external crystal via clock recovery, and LPUART supports wake-up from Stop 2 mode.

Key Specifications

Pinout & Package

LQFP64 package with 64-pin square outline, 0.5 mm pitch, exposed thermal pad, and standard JEDEC MO-110 footprint. Pin functions validated per STMicroelectronics DS12469 Rev 9 Section 4 (Pinouts and pin description) and Table 14 (pin definitions).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L432KBU6, the STM32L412RBI6 offers lower system cost and smaller die size for memory-constrained designs, while the STM32L552RET6 adds security features at significantly higher power and price-making the L412 optimal for cost-sensitive, battery-operated industrial sensing where TrustZone is unnecessary.

Availability

STM32L412RBI6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, wireless sensor nodes, and portable diagnostic tools requiring stable component supply across multi-year production cycles.

Supply support for STM32L412RBI6 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 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 emphasis on battery longevity, rich analog integration, and flexible power management for IoT edge devices.

FAQ

What is the maximum operating frequency and corresponding performance metric?

The STM32L412RBI6 achieves a maximum CPU frequency of 80 MHz, delivering 100 DMIPS (Dhrystone 2.1) and 273.55 CoreMark® (3.42 CoreMark/MHz). This performance is sustained with zero wait states thanks to the ART Accelerator™, which caches flash accesses and eliminates instruction fetch bottlenecks during real-time execution.

Does this MCU support external SMPS, and how does it affect power consumption?

Yes, the STM32L412RBI6 supports external SMPS via the VDD12 pin. When powered by an external SMPS instead of the internal LDO, Run-mode current drops to 28 µA/MHz at 3.3 V-nearly 3× lower than the 79 µA/MHz achieved in LDO mode-enabling extended battery life in always-on sensor applications without compromising processing throughput.

Which low-power modes retain RTC functionality, and what is the associated current draw?

Standby mode with RTC enabled draws 245 nA, and VBAT mode (supplying RTC and backup registers only) consumes 300 nA. Both modes preserve calendar, alarms, and 32×32-bit backup registers. The RTC remains fully functional-including calibration and tamper detection-in these states, making them ideal for time-critical, long-duration monitoring tasks.

Is USB connectivity possible without an external crystal, and what are the timing constraints?

Yes, USB 2.0 Full-Speed operates crystal-less using the internal 48 MHz RC oscillator with Clock Recovery System (CRS). CRS dynamically adjusts the RC frequency to match USB SOF timing, achieving ±0.25% accuracy-within USB specification limits. No external crystal or trimming capacitor is required, reducing BOM count and PCB area.