STM32L071 User Reference Manual Guide

●The access line ultra-low-power STM32L071xx microcontrollers incorporate the connectivity power of the universal serial bus (USB 2.0 crystal-less) with the high-performance ARM® Cortex®-M0+ 32-bit RISC core operating at a 32 MHz frequency, a memory protection unit (MPU), high-speed embedded memories (up to 192 Kbytes of Flash program memory, 6 Kbytes of data EEPROM and 20 Kbytes of RAM) plus an extensive range of enhanced I/Os and peripherals.

●The STM32L071xx devices provide high power efficiency for a wide range of performance. It is achieved with a large choice of internal and external clock sources, an internal voltage adaptation and several low-power modes.

●The STM32L071xx devices offer several analog features, one 12-bit ADC with hardware oversampling, two DACs, two ultra-low-power comparators, AES, several timers, one low-power timer (LPTIM), four general-purpose 16-bit timers and two basic timer, one RTC and one SysTick which can be used as timebases. They also feature two watchdogs, one watchdog with independent clock and window capability and one window watchdog based on bus clock.

●Moreover, the STM32L071xx devices embed standard and advanced communication interfaces: up to three I2Cs, two SPIs, one I2S, four USARTs, a low-power UART (LPUART), and a crystal-less USB. The devices offer up to 19 capacitive sensing channels to simply add touch sensing functionality to any application.

●The STM32L071xx also include a real-time clock and a set of backup registers that remain powered in Standby mode.

●The ultra-low-power STM32L071xx devices operate from a 1.8 to 3.6 V power supply (down to 1.65 V at power down) with BOR and from a 1.65 to 3.6 V power supply without BOR option. They are available in the -40 to +125 °C temperature range. A comprehensive set of power-saving modes allows the design of low-power applications.

●Key Features

● Ultra-low-power platform

● 1.65 V to 3.6 V power supply

● -40 to 125 °C temperature range

● 0.29 μA Standby mode (3 wakeup pins)

● 0.43 μA Stop mode (16 wakeup lines)

● 0.86 μA Stop mode + RTC + 20 KB RAM retention

● Down to 93 μA/MHz in Run mode

● 5 μs wakeup time (from Flash memory)

● 41 μA 12-bit ADC conversion at 10 ksps

● Core: ARM® 32-bit Cortex®-M0+ with MPU

● From 32 kHz up to 32 MHz max.

● 0.95 DMIPS/MHz

● Memories

● Up to 192 KB Flash memory with ECC (2 banks with read-while-write capability)

● 20 KB RAM

● 6 KB of data EEPROM with ECC

● 20-byte backup register

● Sector protection against R/W operation

● Up to 4084 fast I/Os (3478 I/Os 5V tolerant)

● Reset and supply management

● Ultra-safe, low-power BOR (brownout reset) with 5 selectable thresholds

● Ultra-low-power POR/PDR

● Programmable voltage detector (PVD)

● Clock sources

● 1 to 25 MHz crystal oscillator

● 32 kHz oscillator for RTC with calibration

● High speed internal 16 MHz factory-trimmed RC (+/- 1%)

● Internal low-power 37 kHz RC

● Internal multispeed low-power 65 kHz to 4.2 MHz RC

● Internal self calibration of 48 MHz RC for USB

● PLL for CPU clock

● Pre-programmed bootloader

● USB, USART, I2C, SPI supported

● Development support

● Serial wire debug supported

● Rich Analog peripherals

● 12-bit ADC 1.14 Msps up to 16 channels (down to 1.65 V)

● 12-bit ADC 1.14 Msps, up to 13 channels (down to 1.65 V)

● 2 x 12-bit channel DACs with output buffers (down to 1.8 V)

● 2x ultra-low-power comparators (window mode and wake up capability, down to 1.65 V)

● Up to 19 capacitive sensing channels supporting touchkey, linear and rotary touch sensors

● 7-channel DMA controller, supporting ADC, SPI, I2C, USART, DAC, Timers, AES

● 11Up to 10x peripheral communication interfaces

● 1x USB 2.0 crystal-less, battery charging detection and LPM

● 4x USART (2 with ISO 7816, IrDA), 1x UART (low power)

● Up to 6x SPI 16 Mbits/s

● 3x I2C (2 with SMBus/PMBus)

● 11x timers: 2x 16-bit with up to 4 channels, 2x 16-bit with up to 2 channels, 1x 16-bit ultra-low-power timer, 1x SysTick, 1x RTC, 2x 16-bit basic for DAC, and 2x watchdogs (independent/window)

● CRC calculation unit, 96-bit unique ID

● True RNG and firewall protection

● Hardware Encryption Engine AES 128-bit

● All packages are ECOPACK®2