ST公司的STM32L072CZ是超低功耗基于ARM Cortex®-M0+的32位MCU,集成了多达192KB闪存,20KB SRAM,6KB EEPROM以及USB,ADC和DAC等,工作频率32MHz,0.95 DMIPS/MHz,工作电压1.65V-3.6V,工作温度-40到125℃ ,工作时的功耗低至93 μA/MHz,主要用在气体/水表和工业传感器,健康和健全制度设备,遥控和用户接口,PC外设,游戏与GPS设备,告警系统,有线和无线传感器以及视频互连.本文介绍了STM32L072CZ主要特性,框图和时钟树,以及评估板B-L072Z-LRWAN1 Discovery kit主要特性,框图,元件布局图和电路图.

The ultra-low-power STM32L072xx 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 STM32L072xx 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 STM32L072xx devices offer several analog features, one 12-bit ADC with hardware oversampling, two DACs, two ultra-low-power comparators, 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 STM32L072xx 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 24 capacitive sensing channels to simply add touch sensing functionality to any application. The STM32L072xx also include a real-time clock and a set of backup registers that remain powered in Standby mode. The ultra-low-power STM32L072xx 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 ℃ temperature range. A comprehensive set of power-saving modes allows the design of low-power applications.

The ultra-low-power STM32L072xx are offered in 9 different package typesfrom 32 pins to 100 pins. Depending on the device chosen, different sets of peripherals are included, the description below gives an overview of the complete range of peripherals proposed in this family. These features make the ultra-low-power STM32L072xx microcontrollers suitable for a wide range of applications:

• Gas/water meters and industrial sensors

• Healthcare and fitness equipment

• Remote control and user interface

• PC peripherals, gaming, GPS equipment

• Alarm system, wired and wireless sensors, video intercom

STM32L072CZ主要特性:

• 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 84 fast I/Os (78 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 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)

– 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 24 capacitive sensing channels supporting touchkey, linear and rotary touch sensors

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

• 11x 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

• All packages are ECOPACK®2

图1.STM32L072xx框图

图2.STM32L072xx时钟树

评估板B-L072Z-LRWAN1 Discovery kit

The B-L072Z-LRWAN1 Discovery kit embeds the CMWX1ZZABZ-091 LoRa®/Sigfox™ module (Murata). This Discovery kit allows users to develop easily applications with the STM32L072CZ and the LoRa®/Sigfox™ RF connectivity in one single module. The B-L072Z-LRWAN1 Discovery kit has the full set of features available in the STM32L0 Series and offers ultra-low-power and LoRa®/Sigfox™ RF features. The B-L072Z-LRWAN1 Discovery kit is a low-cost and easy-to-use development kit to quickly evaluate and start a development with an STM32L072CZ microcontroller.

The B-L072Z-LRWAN1 Discovery kit includes LoRa®/Sigfox™ RF interface, LEDs, push-buttons, antenna, Arduino™ Uno V3 connectors, USB 2.0 FS connector in Micro-B format. The integrated ST-LINK/V2-1 provides an embedded in-circuit debugger and programmer for the STM32L0 MCUs.

The LoRaWAN™ stack is certified class A and C compliant. It is available inside theI-CUBE-LRWAN firmware package.TheSigfox™ stack is RCZ1, RCZ2, and RCZ4 certified. It is available inside the X-CUBE-SFOX expansion package.

To help users setting up a complete node (LoRaWAN™, Sigfox™, or both), the B-L072Z-LRWAN1 Discovery kit comes with the STM32 comprehensive free software libraries and examples available with the STM32Cube package, as well as a direct access to the Arm® Mbed Enabled™ resources at the http://mbed.org website.

图3.评估板B-L072Z-LRWAN1LoRa®/SigfoxDiscovery kit外形图

评估板B-L072Z-LRWAN1 Discovery kit主要特性:

• CMWX1ZZABZ-091 LoRa®/Sigfox™ module (Murata)

– Embedded ultra-low-power STM32L072CZ Series MCUs, based on Arm® Cortex® -M0+ core, with 192 Kbytes of Flash memory, 20 Kbytes of RAM, 20 Kbytes of EEPROM

– USB 2.0 FS

– 4-channel,12-bit ADC, 2xDAC

– 6-bit timers, LP-UART, I2C and SPI

– Embedded SX1276 transceiver

– LoRa®, FSK, GFSK, MSK, GMSK and OOK modulations (+ Sigfox™ compatibility)

– +14 dBm or +20 dBm selectable output power

– 157 dB maximum link budget

– Programmable bit rate up to 300 kbit/s

– High sensitivity: down to -137 dBm

– Bullet-proof front end: IIP3 = -12.5 dBm

– 89 dB blocking immunity

– Low RX current of 10 mA, 200 nA register retention

– Fully integrated synthesizer with a resolution of 61 Hz

– Built-in bit synchronizer for clock recovery

– Sync word recognition

– Preamble detection

– 127 dB+ dynamic range RSSI

• Including 50 ohm SMA RF antenna

• 1 user and reset push-buttons

• Board connectors:

– USB FS connector

– SMA and U.FL RF

• Board expansion connectors:

– Arduino™ Uno V3 • 7 LEDs:

– 4 general-purpose LEDs

– 5 V-power LED

– ST-LINK-communication LED

– Fault-power LED

• Flexible power-supply options: ST-LINK USB VBUS or external sources

• On-board ST-LINK/V2-1 debugger/programmer with USB re-enumeration capability: mass storage, virtual COM port and debug port

• Comprehensive free software libraries and examples available with the STM32Cube package

• Support of a wide choice of Integrated Development Environments (IDES) including IAR™, Keil®, GCC-based IDEs, Arm® Mbed™

• Arm® Mbed Enabled™ compliant

图4.评估板B-L072Z-LRWAN1LoRa®/SigfoxDiscovery kit硬件框图

图4.评估板B-L072Z-LRWAN1顶层布局图

图5.评估板B-L072Z-LRWAN1底层布局图

图6.评估板B-L072Z-LRWAN1顶层框图

图7.评估板B-L072Z-LRWAN1电路图(1):电源

图8.评估板B-L072Z-LRWAN1电路图(2):ST-LINK/V2-1

图9.评估板B-L072Z-LRWAN1电路图(3):LoRa/Sigfox模块

图10.评估板B-L072Z-LRWAN1电路图(4):USB 2.0 FS和天线

图11.评估板B-L072Z-LRWAN1电路图(5):连接器

STM32L072CZ

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 84 fast I/Os (78 I/Os 5V tolerant)

• Reset and supply management

– Ultra-safe, low-power BOR (brownout reset)

with 5 selectable thresholds

– Ultra-low-power POR/PDR

Rich Analog peripherals

– 12-bit ADC 1.14 Msps up to 16 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 24 capacitive sensing channels supporting

touchkey, linear and rotary touch sensors

• 7-channel DMA controller, supporting ADC, SPI,

I2C, USART, DAC, Timers

• 11x 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

• All packages are ECOPACK®2

Table 1. Device summary

– 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 supported

• Development support

– Serial wire debug supported

Introduction

The ultra-low-power STM32L072xx are offered in 9 different package typesfrom 32 pins to 100 pins. Depending on the device chosen, different sets of peripherals are included, the description below gives an overview of the complete range of peripherals proposed in this family.

These features make the ultra-low-power STM32L072xx microcontrollers suitable for a widerange of applications:

• Gas/water meters and industrial sensors

• Healthcare and fitness equipment

• Remote control and user interface

• PC peripherals, gaming, GPS equipment

• Alarm system, wired and wireless sensors, video intercom

This STM32L072xx datasheet should be read in conjunction with the STM32L0x2xx

reference manual (RM0376).

For information on the Arm® Cortex®-M0+ core please refer to the Cortex®-M0+ Technical

Reference Manual, available from the www.arm.com website.

Figure 1 shows the general block diagram of the device family.

Description

The ultra-low-power STM32L072xx 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), highspeed 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 STM32L072xx 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 STM32L072xx devices offer several analog features, one 12-bit ADC with hardware oversampling, two DACs, two ultra-low-power comparators, 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 STM32L072xx 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 24 capacitive sensing channels to simply add touch sensing functionality to any application.

The STM32L072xx also include a real-time clock and a set of backup registers that remain powered in Standby mode.

The ultra-low-power STM32L072xx 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.