STMicroelectronics STM32L100R8T6ATR

Overview

STM32L100R8T6ATR from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller in LQFP64 package, featuring 128 KB Flash, 16 KB SRAM, 2 KB EEPROM with ECC, integrated LCD driver (8×28 segments), USB 2.0 interface, and dual 12-bit DACs. It operates from 1.8 V to 3.6 V across –40°C to +85°C and targets battery-powered portable instrumentation requiring sub-µA standby current (0.28 µA) and fast wakeup (<8 µs).

For engineers reviewing the STM32L100R8T6ATR datasheet, STM32L100R8T6ATR pinout, STM32L100R8T6ATR application, or STM32L100R8T6ATR equivalent, key selection criteria include ultra-low-power mode timing (Stop/Standby current values), LCD segment drive capability, USB 2.0 PHY integration, DAC output buffer availability, and 51 fast I/Os with 5V tolerance on 42 pins.

Technical Context

The device implements a multi-voltage domain architecture with separate VDD/VSS, VDDA/VSSA, and VLCD rails, enabling independent analog and LCD power management down to 1.8 V. Its clock system integrates six oscillators - HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz), LSI (37 kHz), MSI (65 kHz–4.2 MHz), and USB PLL (48 MHz) - with dynamic voltage scaling for optimized performance vs. power trade-offs.

Peripherals are partitioned across low-power domains: ADC (12-bit, 1 Msps, 24 channels), two ultra-low-power comparators with window mode and wakeup capability, CRC unit, and 7-channel DMA controller. All 10 timers support low-power operation, including two watchdogs (independent and window) and six 16-bit general-purpose timers with up to four PWM/IC/OC channels each.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad; RoHS-compliant, industrial temperature grade (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L100R8T6ATR, STM32L053R8T6 trades LCD/USB for security features and reduced cost, while STM32L432KCU6 shifts focus to performance and flexibility at the expense of ultra-low-power efficiency - making the L100R8 optimal for display-integrated, battery-critical applications.

Availability

STM32L100R8T6ATR is available at Aetrix Electronics and suitable for portable medical devices, smart utility meters, industrial wireless sensor nodes, and wearable health monitors requiring stable component supply across extended product lifecycles.

Supply support for STM32L100R8T6ATR 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 STM32L1 series targets ultra-low-power embedded applications where battery longevity, integrated analog peripherals, and compact display support are critical - exemplified by this part's emphasis on sub-µA standby, on-chip LCD bias, and ECC-protected memory.

FAQ

What is the maximum operating frequency and corresponding power consumption in Run mode?

The STM32L100R8T6ATR achieves up to 32 MHz CPU frequency with 185 µA/MHz typical current consumption when executing code from Flash. At 32 MHz, total active current is approximately 5.9 mA (185 µA × 32), verified under 3.3 V supply and 25°C ambient per datasheet Table 18.

Does this MCU support hardware encryption or secure boot features?

No, the STM32L100R8T6ATR does not integrate hardware cryptographic accelerators (AES, DES, SHA) or secure boot ROM. It relies on software-based security libraries; for hardware security, consider STM32L053 or STM32L4x2 variants which include AES-128 and public-key accelerators.

Can the internal 32.768 kHz LSE oscillator be calibrated for improved RTC accuracy?

Yes, the LSE oscillator supports automatic calibration against the HSE or HSI clock source, achieving ±1 ppm accuracy after calibration. The calibration value is stored in backup registers and persists across resets, enabling high-precision timekeeping in battery-backed RTC applications.

Is the USB interface fully self-contained, or does it require external components?

The USB 2.0 Full-Speed interface is fully integrated with an internal PHY, requiring only standard USB-series resistors (1.5 kΩ pull-up on D+, 22 Ω series on D+/D−) and proper PCB layout per AN4879. No external transceiver or voltage-level shifter is needed for basic enumeration and CDC/DFU operation.