STMicroelectronics STM32L100R8T6A

Overview

STM32L100R8T6A 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 STM32L100R8T6A datasheet, STM32L100R8T6A pinout, STM32L100R8T6A application, or STM32L100R8T6A equivalent, key selection criteria include verified low-power mode current specs (e.g., 1.38 µA Stop+RTC), LCD segment drive capability, USB 2.0 PHY integration, 12-bit ADC (1 Msps, 24-channel), and dual buffered DAC performance under 1.8 V operation.

Technical Context

The STM32L100R8T6A implements a single-core ARM Cortex-M3 CPU running up to 32 MHz with MPU, supported by multiple clock sources including HSE (1–24 MHz), LSE (32.768 kHz RTC), HSI (16 MHz), LSI (37 kHz), and MSI (65 kHz–4.2 MHz). Its power architecture enables dynamic voltage scaling and five low-power modes-Run, Sleep, Low-power Run, Stop, and Standby-with dedicated regulators and brownout reset (BOR) having five programmable thresholds.

Analog subsystem includes a 12-bit ADC with up to 24 channels, two 12-bit DACs with output buffers, two ultra-low-power comparators with window mode and wakeup capability, and internal voltage reference (VREFINT). The integrated LCD controller supports contrast adjustment and blinking, with on-board step-up converter for VLCD rail generation.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed pad for thermal dissipation; 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 STM32L071RBT6 and STM32L432KCU6, the STM32L100R8T6A uniquely balances ultra-low-power operation, integrated LCD driving, and analog peripherals in a cost-optimized Cortex-M3 platform-making it optimal for display-centric, battery-limited devices where EEPROM retention and sub-µA standby are mandatory.

Availability

STM32L100R8T6A is available at Aetrix Electronics and suitable for portable medical devices, smart utility meters, wearable health trackers, and industrial sensor nodes requiring stable component supply across extended product lifecycles.

Supply support for STM32L100R8T6A 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, emphasizing energy efficiency, integrated analog peripherals, and long-term reliability in battery-operated and energy-harvesting systems.

FAQ

What is the maximum operating frequency and core type of the STM32L100R8T6A?

The STM32L100R8T6A features an ARM Cortex-M3 32-bit core rated for up to 32 MHz operation. It achieves 1.25 DMIPS/MHz (Dhrystone 2.1) and includes a Memory Protection Unit (MPU) for enhanced system robustness. The maximum frequency is sustained across the full 1.8–3.6 V supply range and –40°C to +85°C temperature span, with dynamic voltage scaling optimizing power versus performance.

Does the STM32L100R8T6A support USB device functionality without external components?

Yes - the STM32L100R8T6A integrates a full-speed USB 2.0 device interface with an internal 48 MHz PLL and on-die transceiver. It requires only standard USB termination resistors (1.5 kΩ pull-up on D+) and proper PCB layout; no external PHY, level shifters, or ESD protection diodes are needed for basic enumeration and data transfer.

How many I/O pins are 5V-tolerant, and what is their safe operating voltage range?

42 of the 51 general-purpose I/O pins on the STM32L100R8T6A are 5V-tolerant when configured as inputs or outputs in push-pull or open-drain mode. They safely accept input voltages up to 5.5 V regardless of VDD level (1.8–3.6 V), enabling direct interfacing with legacy 5V logic, sensors, or displays without external level translators.

What LCD configuration does the STM32L100R8T6A support, and how is contrast controlled?

The STM32L100R8T6A supports up to 8 commons and 28 segments (8×28) for static or multiplexed segmented LCDs. Contrast is adjusted digitally via the LCD_CR register's CC[3:0] bits, selecting one of 16 internal voltage divider taps. An on-chip step-up converter generates VLCD (up to 5.5 V) from VDD, eliminating need for external charge pumps in most display configurations.