STMicroelectronics STM32L100R8T6

Overview

STM32L100R8T6 from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller with 128 KB Flash, 10 KB SRAM, 2 KB EEPROM, integrated LCD driver, 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 achieves 214 µA/MHz active current consumption. It targets battery-powered portable instrumentation requiring precise analog signal generation and display control.

For engineers reviewing the STM32L100R8T6 datasheet, STM32L100R8T6 pinout, STM32L100R8T6 application, or STM32L100R8T6 equivalent, key selection criteria include standby current (0.3 µA), LCD segment drive capability (up to 8×28), USB 2.0 full-speed support, 12-bit ADC with 1 Msps sampling, and 51 fast I/Os with 42 5V-tolerant pins - all within the LQFP64 package.

Technical Context

The STM32L100R8T6 integrates a 32 MHz Cortex-M3 core with MPU, dynamic voltage scaling, and seven low-power modes including Stop (0.57 µA) and Standby (0.3 µA). Its clock system combines HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz), LSI (37 kHz), and MSI (65 kHz–4.2 MHz) sources, plus a PLL for USB clock generation at 48 MHz.

Analog subsystem includes two independent 12-bit DACs with output buffers, a 20-channel 12-bit ADC (1 Msps), two ultra-low-power comparators, and internal voltage reference (VREFINT). The LCD controller supports static and multiplexed segments up to 8 commons × 28 segments with built-in bias generation and contrast control.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad - optimized for thermal dissipation and manual soldering in industrial and portable applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L053R8T6, the STM32L100R8T6 offers integrated LCD control and larger Flash; versus STM32L432KCU6, it trades CPU performance and memory for ultra-low-power operation and display capability - making it optimal for battery-powered segment-display applications.

Availability

STM32L100R8T6 is available at Aetrix Electronics and suitable for portable medical monitors, smart utility meters, industrial sensor nodes, and wearable health trackers requiring stable component supply and long-term lifecycle support.

Supply support for STM32L100R8T6 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 STM32L100 series belongs to ST's ultra-low-power MCU product line, engineered specifically for battery-operated applications demanding extended runtime, integrated peripherals (LCD, USB, DAC), and robust memory reliability - without sacrificing ARM Cortex-M3 programmability.

FAQ

What is the maximum operating frequency of the STM32L100R8T6?

The STM32L100R8T6 runs at up to 32 MHz using its internal 16 MHz HSI oscillator multiplied by the PLL, or directly from an external crystal up to 24 MHz. Its Cortex-M3 core delivers 1.25 DMIPS/MHz, achieving ~40 DMIPS at full speed - sufficient for real-time sensor processing and USB protocol handling without overclocking.

Does the STM32L100R8T6 support USB device functionality without external components?

Yes - the STM32L100R8T6 integrates a full-speed USB 2.0 device controller with internal transceiver. Only two 1.5 kΩ pull-up resistors on D+ (for full-speed enumeration) and standard USB termination capacitors are required. It supports CDC, HID, and DFU classes out-of-the-box using ST's USB middleware libraries.

How many LCD segments can the STM32L100R8T6 drive, and what bias configuration does it support?

The STM32L100R8T6 drives up to 8 commons × 28 segments (224 total) in static, 2-, 3-, or 4-mux configurations. It includes an internal charge pump for adjustable bias voltage (VLCD), programmable contrast control, and software-configurable duty/cycle settings - enabling direct drive of common segment LCD glass without external bias generators.

What are the key low-power modes and their typical current draws?

The STM32L100R8T6 offers six low-power modes: Sleep (122 µA @ 32 MHz), Low-power Run (9 µA), Low-power Sleep (12.5 µA), Stop (0.57 µA), Stop + RTC (1.2 µA), and Standby (0.3 µA). All retain SRAM and register content except Standby, which wakes in <8 µs - ideal for intermittent sensing with rapid response requirements.