STMicroelectronics STM32L475RET6

Overview

STM32L475RET6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 512 KB Flash, 128 KB SRAM, USB OTG FS, dual SAI audio interfaces, and integrated analog peripherals including three 12-bit ADCs (5 Msps) and two 12-bit DACs. It targets battery-powered IoT edge nodes, portable medical sensors, and industrial wireless gateways requiring sustained operation under 1.71–3.6 V supply.

For engineers reviewing the STM32L475RET6 datasheet, STM32L475RET6 pinout, STM32L475RET6 application, or STM32L475RET6 equivalent, key selection criteria include its 420 nA Standby-with-RTC current, ART Accelerator™ enabling zero-wait-state Flash execution, 114 GPIOs (most 5 V-tolerant), and hardware cryptographic support via TRNG and CRC unit - all in LQFP64 package.

Technical Context

The STM32L475RET6 implements a dual-bank Flash architecture supporting read-while-write and proprietary code readout protection (RDP Level 2). Its FlexPowerControl system enables seven low-power modes - including Stop 2 (1.1 µA) and Shutdown (30 nA) - with sub-4 µs wakeup latency and hardware calendar RTC with calibration.

It integrates three independent analog domains: one for 3× 12-bit ADCs (200 µA/Msps), another for 2× op-amps with PGA, and a third for 2× ultra-low-power comparators - all powered separately to minimize noise coupling. Clocking includes three PLLs (system/USB/audio), auto-trimmed MSI (±0.25%), and external 4–48 MHz/32 kHz crystal support.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad; RoHS-compliant and ECOPACK2® certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L432KCU6, the STM32L475RET6 adds dual SAI, USB OTG, and higher analog integration - essential for audio and host-connected edge devices; versus STM32U575ZIT6, it trades advanced security and efficiency for mature toolchain support and lower unit cost in volume production.

Availability

STM32L475RET6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, industrial wireless sensor nodes, and audio edge gateways requiring stable component supply across multi-year production cycles.

Supply support for STM32L475RET6 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 semiconductors since 1987.

The STM32L4 series targets ultra-low-power embedded applications demanding high performance-per-microwatt, with emphasis on battery longevity, rich analog integration, and robust security primitives for IoT endpoints.

FAQ

What is the maximum operating frequency and associated performance metric?

The STM32L475RET6 runs at up to 80 MHz with its Arm Cortex-M4 core, achieving 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 without requiring external memory or complex prefetch logic.

How does the low-power architecture support multi-year battery operation?

It achieves multi-year operation through hierarchical power gating: Shutdown mode draws just 30 nA (with 5 wakeup pins), Standby-with-RTC consumes 420 nA, and Stop 2 mode uses 1.1 µA. Combined with sub-4 µs wakeup latency and hardware RTC calendar, it enables precise duty cycling - e.g., waking every 30 seconds for sensor reads and BLE advertising bursts.

Which communication interfaces support audio-class timing and synchronization?

The device integrates two Serial Audio Interfaces (SAI1 and SAI2), each supporting I²S, PCM, and AC97 protocols with independent master clocks, programmable bit clock dividers, and FIFO buffering. These interfaces synchronize directly with the audio PLL and support TDM up to 32 slots - enabling multi-microphone array processing without CPU intervention.

Can the internal ADCs operate concurrently with other peripherals without performance degradation?

Yes - three independent 12-bit ADCs can sample simultaneously using hardware triggers (e.g., TIM1 CC1, LPTIM1 OUT), with dedicated DMA channels and configurable resolution (6–16 bits via oversampling). Their separate VDDA supply and internal voltage reference buffer (VREFBUF) ensure <±1 LSB INL even during heavy digital activity on VDD.