STM32L052x6 STM32L052x8
Ultra-low-power 32-bit MCU Arm®-based Cortex®-M0+, up to 64 KB
Flash memory, 8 KB SRAM, 2 KB EEPROM, USB, ADC, DAC
Datasheet - production data
Features
FBGA
Includes ST state-of-the-art patented
technology
• Ultra-low-power platform
– 1.65 V to 3.6 V power supply
– -40 to 125 °C temperature range
– 0.27 µA Standby mode (2 wakeup pins)
– 0.4 µA Stop mode (16 wakeup lines)
– 0.8 µA Stop mode + RTC + 8-Kbyte RAM
retention
– 88 µA/MHz in Run mode
– 3.5 µs wakeup time (from RAM)
– 5 µs wakeup time (from Flash memory)
• Core: Arm® 32-bit Cortex®-M0+ with MPU
– From 32 kHz up to 32 MHz max.
– 0.95 DMIPS/MHz
• Memories
– Up to 64-Kbyte Flash memory with ECC
– 8-Kbyte RAM
– 2 Kbytes of data EEPROM with ECC
– 20-byte backup register
– Sector protection against R/W operation
• Up to 51 fast I/Os (45 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 factorytrimmed 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
– USART, SPI supported
February 2021
This is information on a product in full production.
LQFP32 (7x7 mm)
LQFP48 (7x7 mm)
LQFP64 (10x10 mm)
UFQFPN32
(5x5 mm)
UFQFPN48
(7x7 mm)
Standard and
thin WLCSP36
(2.61x2.88 mm)
TFBGA64
(5x5 mm)
• 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 1 channel DAC 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
• 8x peripheral communication interfaces
– 1x USB 2.0 crystal-less, battery charging
detection and LPM
– 2x USART (ISO 7816, IrDA), 1x UART (low
power)
– Up to 4x SPI 16 Mbits/s
– 2x I2C (SMBus/PMBus)
• 9x timers: 1x 16-bit with up to 4 channels, 2x
16-bit with up to 2 channels, 1x 16-bit ultra-lowpower timer, 1x SysTick, 1x RTC, 1x 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 ECOPACK2
Table 1. Device summary
Reference
Part number
STM32L052x6
STM32L052C6, STM32L052K6,
STM32L052R6, STM32L052T6
STM32L052x8
STM32L052C8, STM32L052K8,
STM32L052R8, STM32L052T8
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www.st.com
Contents
STM32L052x6 STM32L052x8
Contents
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3
2.1
Device overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2
Ultra-low-power device continuum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.1
Low-power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2
Interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.3
Arm® Cortex®-M0+ core with MPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.4
Reset and supply management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4.1
Power supply schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4.2
Power supply supervisor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4.3
Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.5
Clock management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.6
Low-power real-time clock and backup registers . . . . . . . . . . . . . . . . . . . 27
3.7
General-purpose inputs/outputs (GPIOs) . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.8
Memories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.9
Boot modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.10
Direct memory access (DMA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.11
Analog-to-digital converter (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.12
Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.12.1
2/150
Internal voltage reference (VREFINT) . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.13
Digital-to-analog converter (DAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.14
Ultra-low-power comparators and reference voltage . . . . . . . . . . . . . . . . 31
3.15
System configuration controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.16
Touch sensing controller (TSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.17
Timers and watchdogs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.17.1
General-purpose timers (TIM2, TIM21 and TIM22) . . . . . . . . . . . . . . . . 33
3.17.2
Low-power Timer (LPTIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.17.3
Basic timer (TIM6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.17.4
SysTick timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
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Contents
3.17.5
Independent watchdog (IWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.17.6
Window watchdog (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Communication interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.18.1
I2C bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.18.2
Universal synchronous/asynchronous receiver transmitter (USART) . . 35
3.18.3
Low-power universal asynchronous receiver transmitter (LPUART) . . . 36
3.18.4
Serial peripheral interface (SPI)/Inter-integrated sound (I2S) . . . . . . . . 36
3.18.5
Universal serial bus (USB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.19
Clock recovery system (CRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.20
Cyclic redundancy check (CRC) calculation unit . . . . . . . . . . . . . . . . . . . 37
3.21
Serial wire debug port (SW-DP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4
Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5
Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
6
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1
Parameter conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.1
Minimum and maximum values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.2
Typical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.3
Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.4
Loading capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.5
Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6.1.6
Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
6.1.7
Current consumption measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
6.2
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
6.3
Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
6.3.1
General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
6.3.2
Embedded reset and power control block characteristics . . . . . . . . . . . 60
6.3.3
Embedded internal reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.3.4
Supply current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.3.5
Wakeup time from low-power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
6.3.6
External clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.3.7
Internal clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.3.8
PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.3.9
Memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.3.10
EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
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STM32L052x6 STM32L052x8
6.3.11
Electrical sensitivity characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.3.12
I/O current injection characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
6.3.13
I/O port characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.3.14
NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
6.3.15
12-bit ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
6.3.16
DAC electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6.3.17
Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6.3.18
Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6.3.19
Timer characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.3.20
Communications interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.1
LQFP64 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
7.2
TFBGA64 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119
7.3
LQFP48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.4
UFQFPN48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
7.5
Standard WLCSP36 package information . . . . . . . . . . . . . . . . . . . . . . . 128
7.6
Thin WLCSP36 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
7.7
LQFP32 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
7.8
UFQFPN32 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
7.9
Thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
7.9.1
Reference document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
8
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
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DS10182 Rev 10
STM32L052x6 STM32L052x8
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
Table 19.
Table 20.
Table 21.
Table 22.
Table 23.
Table 24.
Table 25.
Table 26.
Table 27.
Table 28.
Table 29.
Table 30.
Table 31.
Table 32.
Table 33.
Table 34.
Table 35.
Table 36.
Table 37.
Table 38.
Table 39.
Table 40.
Table 41.
Table 42.
Table 43.
Table 44.
Table 45.
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Ultra-low-power STM32L052x6/x8 device features and peripheral counts. . . . . . . . . . . . . 12
Functionalities depending on the operating power supply range . . . . . . . . . . . . . . . . . . . . 18
CPU frequency range depending on dynamic voltage scaling . . . . . . . . . . . . . . . . . . . . . . 18
Functionalities depending on the working mode
(from Run/active down to standby) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
STM32L052x6/8 peripherals interconnect matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Temperature sensor calibration values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Internal voltage reference measured values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Capacitive sensing GPIOs available on STM32L052x6/8 devices . . . . . . . . . . . . . . . . . . . 32
Timer feature comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Comparison of I2C analog and digital filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
STM32L052x6/8 I2C implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
USART implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SPI/I2S implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Legend/abbreviations used in the pinout table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
STM32L052x6/8 pin definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Alternate function port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Alternate function port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Alternate function port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Alternate function port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Alternate function port H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Embedded reset and power control block characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 60
Embedded internal reference voltage calibration values . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Embedded internal reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Current consumption in Run mode, code with data processing running from Flash. . . . . . 63
Current consumption in Run mode vs code type,
code with data processing running from Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Current consumption in Run mode, code with data processing running from RAM . . . . . . 65
Current consumption in Run mode vs code type,
code with data processing running from RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Current consumption in Sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Current consumption in Low-power run mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Current consumption in Low-power sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Typical and maximum current consumptions in Stop mode . . . . . . . . . . . . . . . . . . . . . . . . 69
Typical and maximum current consumptions in Standby mode . . . . . . . . . . . . . . . . . . . . . 70
Average current consumption during Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Peripheral current consumption in Run or Sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Peripheral current consumption in Stop and Standby mode . . . . . . . . . . . . . . . . . . . . . . . 73
Low-power mode wakeup timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
High-speed external user clock characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Low-speed external user clock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
HSE oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
LSE oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
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List of tables
Table 46.
Table 47.
Table 48.
Table 49.
Table 50.
Table 51.
Table 52.
Table 53.
Table 54.
Table 55.
Table 56.
Table 57.
Table 58.
Table 59.
Table 60.
Table 61.
Table 62.
Table 63.
Table 64.
Table 65.
Table 66.
Table 67.
Table 68.
Table 69.
Table 70.
Table 71.
Table 72.
Table 73.
Table 74.
Table 75.
Table 76.
Table 77.
Table 78.
Table 79.
Table 80.
Table 81.
Table 82.
Table 83.
Table 84.
Table 85.
Table 86.
Table 87.
Table 88.
Table 89.
Table 90.
Table 91.
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STM32L052x6 STM32L052x8
16 MHz HSI16 oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
HSI48 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
LSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
MSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
RAM and hardware registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Flash memory and data EEPROM characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Flash memory and data EEPROM endurance and retention . . . . . . . . . . . . . . . . . . . . . . . 83
EMS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
EMI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
ESD absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Electrical sensitivities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
I/O current injection susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
I/O static characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Output voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
I/O AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
RAIN max for fADC = 16 MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
ADC accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
DAC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Temperature sensor calibration values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Comparator 1 characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Comparator 2 characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
TIMx characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
I2C analog filter characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
SPI characteristics in voltage Range 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
SPI characteristics in voltage Range 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
SPI characteristics in voltage Range 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
I2S characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
USB startup time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
USB DC electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
USB: full speed electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
LQFP64 - 64-pin, 10 x 10 mm low-profile quad flat
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
TFBGA64 – 64-ball, 5 x 5 mm, 0.5 mm pitch thin profile fine pitch ball grid
array package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
TFBGA64 recommended PCB design rules (0.5 mm pitch BGA). . . . . . . . . . . . . . . . . . . 120
LQFP48 - 48-pin, 7 x 7 mm low-profile quad flat package mechanical data. . . . . . . . . . . 123
UFQFPN48 - 48 leads, 7x7 mm, 0.5 mm pitch, ultra thin fine pitch quad flat
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Standard WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Standard WLCSP36 recommended PCB design rules. . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Thin WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
WLCSP36 recommended PCB design rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
LQFP32 - 32-pin, 7 x 7 mm low-profile quad flat package mechanical data. . . . . . . . . . . 135
UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
DS10182 Rev 10
STM32L052x6 STM32L052x8
Table 92.
List of tables
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
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7
List of figures
STM32L052x6 STM32L052x8
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Figure 16.
Figure 17.
Figure 18.
Figure 19.
Figure 20.
Figure 21.
Figure 22.
Figure 23.
Figure 24.
Figure 25.
Figure 26.
Figure 27.
Figure 28.
Figure 29.
Figure 30.
Figure 31.
Figure 32.
Figure 33.
Figure 34.
Figure 35.
Figure 36.
Figure 37.
Figure 38.
Figure 39.
Figure 40.
Figure 41.
Figure 42.
8/150
STM32L052x6/8 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Clock tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
STM32L052x6/8 LQFP64 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
STM32L052x6/8 TFBGA64 ballout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
STM32L052x6/8 LQFP48 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
STM32L052x6/8 UFQFPN48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
STM32L052x6/8 WLCSP36 ballout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
STM32L052x6/8 LQFP32 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
STM32L052x6/8 UFQFPN32 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Pin loading conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Current consumption measurement scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
IDD vs VDD, at TA= 25/55/85/105 °C, Run mode, code running from
Flash memory, Range 2, HSE, 1WS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
IDD vs VDD, at TA= 25/55/85/105 °C, Run mode, code running from
Flash memory, Range 2, HSI16, 1WS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
IDD vs VDD, at TA= 25/55/ 85/105/125 °C, Low-power run mode, code running
from RAM, Range 3, MSI (Range 0) at 64 KHz, 0 WS . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
IDD vs VDD, at TA= 25/55/ 85/105/125 °C, Stop mode with RTC enabled
and running on LSE Low drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
IDD vs VDD, at TA= 25/55/85/105/125 °C, Stop mode with RTC disabled,
all clocks OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
High-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Low-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
HSE oscillator circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Typical application with a 32.768 kHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
HSI16 minimum and maximum value versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . 79
VIH/VIL versus VDD (CMOS I/Os) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
VIH/VIL versus VDD (TTL I/Os) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
I/O AC characteristics definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Recommended NRST pin protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
ADC accuracy characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Typical connection diagram using the ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Power supply and reference decoupling (VREF+ not connected to VDDA) . . . . . . . . . . . . . 97
Power supply and reference decoupling (VREF+ connected to VDDA). . . . . . . . . . . . . . . . . 98
12-bit buffered/non-buffered DAC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
SPI timing diagram - slave mode and CPHA = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
SPI timing diagram - slave mode and CPHA = 1(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
SPI timing diagram - master mode(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
I2S slave timing diagram (Philips protocol)(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
I2S master timing diagram (Philips protocol)(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
USB timings: definition of data signal rise and fall time . . . . . . . . . . . . . . . . . . . . . . . . . . 113
LQFP64 - 64-pin, 10 x 10 mm low-profile quad flat package outline . . . . . . . . . . . . . . . . 115
LQFP64 - 64-pin, 10 x 10 mm low-profile quad flat recommended footprint . . . . . . . . . . 117
LQFP64 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
TFBGA64 – 64-ball, 5 x 5 mm, 0.5 mm pitch thin profile fine pitch ball
grid array package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
DS10182 Rev 10
STM32L052x6 STM32L052x8
Figure 43.
Figure 44.
Figure 45.
Figure 46.
Figure 47.
Figure 48.
Figure 49.
Figure 50.
Figure 51.
Figure 52.
Figure 53.
Figure 54.
Figure 55.
Figure 56.
Figure 57.
Figure 58.
Figure 59.
Figure 60.
Figure 61.
Figure 62.
Figure 63.
List of figures
TFBGA64 – 64-ball, 5 x 5 mm, 0.5 mm pitch, thin profile fine pitch ball
,grid array recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
TFBGA64 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
LQFP48 - 48-pin, 7 x 7 mm low-profile quad flat package outline . . . . . . . . . . . . . . . . . . 122
LQFP48 - 48-pin, 7 x 7 mm low-profile quad flat recommended footprint . . . . . . . . . . . . 123
LQFP48 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
UFQFPN48 - 48 leads, 7x7 mm, 0.5 mm pitch, ultra thin fine pitch quad flat
package outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
UFQFPN48 - 48 leads, 7x7 mm, 0.5 mm pitch, ultra thin fine pitch quad flat
package recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
UFQFPN48 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Standard WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
package outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Standard WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Standard WLCSP36 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . 130
Thin WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
package outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Thin WLCSP36 - 2.61 x 2.88 mm, 0.4 mm pitch wafer level chip scale
package recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Standard WLCSP36 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . 133
LQFP32 - 32-pin, 7 x 7 mm low-profile quad flat package outline . . . . . . . . . . . . . . . . . . 134
LQFP32 - 32-pin, 7 x 7 mm low-profile quad flat recommended footprint . . . . . . . . . . . . 135
LQFP32 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
package outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine pitch quad flat
recommended footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
UFQFPN32 marking example (package top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Thermal resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
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Introduction
1
STM32L052x6 STM32L052x8
Introduction
The ultra-low-power STM32L052x6/8 are offered in 8 different package types: from 32 pins
to 64 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 STM32L052x6/8 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
This STM32L052x6/8 datasheet should be read in conjunction with the STM32L0x2xx
reference manual (RM0376).
For information on the Arm®(a) 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.
a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.
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2
Description
Description
The ultra-low-power STM32L052x6/8 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 (64 Kbytes of Flash program memory, 2 Kbytes of data
EEPROM and 8 Kbytes of RAM) plus an extensive range of enhanced I/Os and peripherals.
The STM32L052x6/8 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 STM32L052x6/8 devices offer several analog features, one 12-bit ADC with hardware
oversampling, one DAC, two ultra-low-power comparators, several timers, one low-power
timer (LPTIM), three general-purpose 16-bit timers and one 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 STM32L052x6/8 devices embed standard and advanced communication
interfaces: up to two I2C, two SPIs, one I2S, two 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 STM32L052x6/8 also include a real-time clock and a set of backup registers that
remain powered in Standby mode.
The ultra-low-power STM32L052x6/8 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.
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37
Description
2.1
STM32L052x6 STM32L052x8
Device overview
Table 2. Ultra-low-power STM32L052x6/x8 device features and peripheral counts
Peripheral
STM32L0
52T6
STM32
L052K6
STM32
L052C6
STM32
L052R6
STM32L
052T8
STM32
L052K8
STM32
L052C8
Flash (Kbytes)
32
64
Data EEPROM (Kbytes)
2
2
RAM (Kbytes)
8
8
Generalpurpose
3
3
Basic
1
1
LPTIMER
1
1
1/1/1/1
1/1/1/1
Timers
RTC/SYSTICK/IWDG/
WWDG
3(2)(1)/0
SPI/I2S
I2C
Communic
ation
interfaces
2
4(2)(1)/1
1
USART
LPUART
2
2
1
0
1
1/(0)
37
Clocks:
HSE/LSE/HSI/MSI/LSI
0/1/1/1/1
0/1/1/1/1
1/1/1/1/1
12-bit synchronized
ADC
Number of channels
1
10
1
10
1
10
12-bit DAC
Number of channels
1
1/(1)
27(2)
51(3)
0
1
1/(1)
27(2)
29
37
1/1/1/1/1 0/1/1/1/1 0/1/1/1/1
1
16(3)
1
10
51(3)
1/1/1/1/1 1/1/1/1/1
1
10
1
1
1
10
1
16(3)
17
24(3)
1
1
2
14
17
24(3)
Max. CPU frequency
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2
1/(0)
Comparators
Operating voltage
1
2
29
Capacitive sensing
channels
4(2)(1)/1
2
USB/
(VDD_USB)
GPIOs
3(2)(1)/0
STM32
L052R8
14
32 MHz
1.8 V to 3.6 V (down to 1.65 V at power-down) with BOR option
1.65 V to 3.6 V without BOR option
DS10182 Rev 10
STM32L052x6 STM32L052x8
Description
Table 2. Ultra-low-power STM32L052x6/x8 device features and peripheral counts (continued)
Peripheral
STM32L0
52T6
STM32
L052K6
STM32
L052R6
STM32L
052T8
STM32
L052K8
STM32
L052C8
STM32
L052R8
Ambient temperature: –40 to +125 °C
Junction temperature: –40 to +130 °C
Operating temperatures
Packages
STM32
L052C6
WLCSP
36
LQFP32,
UFQFPN
32
LQFP48
UFQFPN
48
LQFP64
TFBGA
64
WLCSP
36
LQFP32, LQFP48 LQFP64
UFQFPN UFQFPN TFBGA
32
64
48
1. 2 SPI interfaces are USARTs operating in SPI master mode.
2. LQFP32 has two GPIOs, less than UFQFPN32 (27).
3. TFBGA64 has one GPIO, one ADC input and one capacitive sensing channel less than LQFP64.
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37
Description
STM32L052x6 STM32L052x8
Figure 1. STM32L052x6/8 block diagram
Temp
sensor
SWD
SWD
FLASH
EEPROM
BOOT
FIREWALL
CORTEX M0+ CPU
Fmax:32MHz
ADC1
AINx
SPI1
MISO, MOSI,
SCK, NSS
USART1
RX, TX, RTS,
CTS, CK
RAM
MPU
DBG
DMA1
NVIC
EXTI
A
P
B
2
TIM21
2ch
TIM22
2ch
BRIDGE
COMP1
INP, INM, OUT
COMP2
INP, INM, OUT
BRIDGE
LPTIM1
IN1, IN2,
ETR, OUT
RAM 1K
USB 2.0 FS
TIM6
DAC1
WWDG
I2C1
SCL, SDA,
SMBA
I2C2
SCL, SDA,
SMBA
TSC
CRC
GPIO PORT A
PB[0:15]
GPIO PORT B
PC[0:15]
GPIO PORT C
PD[2]
PH[0:1]
OSC_IN,
OSC_OUT
RNG
AHB: Fmax 32MHz
PA[0:15]
A
P
B
1
GPIO PORT D
GPIO PORT H
HSE
HSI 16M
HSI 48M
CRS
LSI
IWDG
PLL
MSI
DP, DM, OE,
CRS_SYNC,
VDD_USB
OUT1
USART2
RX, TX, RTS,
CTS, CK
LPUART1
RX, TX, RTS,
CTS
SPI2/I2S
MISO/MCK,
MOSI/SD,
SCK/CK, NSS/
WS
TIM2
4ch
RTC
BCKP REG
RESET & CLK
WKUPx
OSC32_IN,
OSC32_OUT
LSE
PVD_IN
VREF_OUT
PMU
NRST
VDDA
VDD
REGULATOR
MS3388V1
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DS10182 Rev 10
STM32L052x6 STM32L052x8
2.2
Description
Ultra-low-power device continuum
The ultra-low-power family offers a large choice of core and features, from 8-bit proprietary
core up to Arm® Cortex®-M4, including Arm® Cortex®-M3 and Arm® Cortex®-M0+. The
STM32Lx series are the best choice to answer your needs in terms of ultra-low-power
features. The STM32 ultra-low-power series are the best solution for applications such as
gaz/water meter, keyboard/mouse or fitness and healthcare application. Several built-in
features like LCD drivers, dual-bank memory, low-power run mode, operational amplifiers,
128-bit AES, DAC, crystal-less USB and many other definitely help you building a highly
cost optimized application by reducing BOM cost. STMicroelectronics, as a reliable and
long-term manufacturer, ensures as much as possible pin-to-pin compatibility between all
STM8Lx and STM32Lx on one hand, and between all STM32Lx and STM32Fx on the other
hand. Thanks to this unprecedented scalability, your legacy application can be upgraded to
respond to the latest market feature and efficiency requirements.
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Functional overview
STM32L052x6 STM32L052x8
3
Functional overview
3.1
Low-power modes
The ultra-low-power STM32L052x6/8 support dynamic voltage scaling to optimize its power
consumption in Run mode. The voltage from the internal low-drop regulator that supplies
the logic can be adjusted according to the system’s maximum operating frequency and the
external voltage supply.
There are three power consumption ranges:
•
Range 1 (VDD range limited to 1.71-3.6 V), with the CPU running at up to 32 MHz
•
Range 2 (full VDD range), with a maximum CPU frequency of 16 MHz
•
Range 3 (full VDD range), with a maximum CPU frequency limited to 4.2 MHz
Seven low-power modes are provided to achieve the best compromise between low-power
consumption, short startup time and available wakeup sources:
•
Sleep mode
In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can
wake up the CPU when an interrupt/event occurs. Sleep mode power consumption at
16 MHz is about 1 mA with all peripherals off.
•
Low-power run mode
This mode is achieved with the multispeed internal (MSI) RC oscillator set to the lowspeed clock (max 131 kHz), execution from SRAM or Flash memory, and internal
regulator in low-power mode to minimize the regulator's operating current. In Lowpower run mode, the clock frequency and the number of enabled peripherals are both
limited.
•
Low-power sleep mode
This mode is achieved by entering Sleep mode with the internal voltage regulator in
low-power mode to minimize the regulator’s operating current. In Low-power sleep
mode, both the clock frequency and the number of enabled peripherals are limited; a
typical example would be to have a timer running at 32 kHz.
When wakeup is triggered by an event or an interrupt, the system reverts to the Run
mode with the regulator on.
Stop mode with RTC
The Stop mode achieves the lowest power consumption while retaining the RAM and
register contents and real time clock. All clocks in the VCORE domain are stopped, the
PLL, MSI RC, HSE crystal and HSI RC oscillators are disabled. The LSE or LSI is still
running. The voltage regulator is in the low-power mode.
Some peripherals featuring wakeup capability can enable the HSI RC during Stop
mode to detect their wakeup condition.
The device can be woken up from Stop mode by any of the EXTI line, in 3.5 µs, the
processor can serve the interrupt or resume the code. The EXTI line source can be any
GPIO. It can be the PVD output, the comparator 1 event or comparator 2 event
(if internal reference voltage is on), it can be the RTC alarm/tamper/timestamp/wakeup
events, the USB/USART/I2C/LPUART/LPTIMER wakeup events.
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DS10182 Rev 10
STM32L052x6 STM32L052x8
•
Functional overview
Stop mode without RTC
The Stop mode achieves the lowest power consumption while retaining the RAM and
register contents. All clocks are stopped, the PLL, MSI RC, HSI and LSI RC, HSE and
LSE crystal oscillators are disabled.
Some peripherals featuring wakeup capability can enable the HSI RC during Stop
mode to detect their wakeup condition.
The voltage regulator is in the low-power mode. The device can be woken up from Stop
mode by any of the EXTI line, in 3.5 µs, the processor can serve the interrupt or
resume the code. The EXTI line source can be any GPIO. It can be the PVD output, the
comparator 1 event or comparator 2 event (if internal reference voltage is on). It can
also be wakened by the USB/USART/I2C/LPUART/LPTIMER wakeup events.
•
Standby mode with RTC
The Standby mode is used to achieve the lowest power consumption and real time
clock. The internal voltage regulator is switched off so that the entire VCORE domain is
powered off. The PLL, MSI RC, HSE crystal and HSI RC oscillators are also switched
off. The LSE or LSI is still running. After entering Standby mode, the RAM and register
contents are lost except for registers in the Standby circuitry (wakeup logic, IWDG,
RTC, LSI, LSE Crystal 32 KHz oscillator, RCC_CSR register).
The device exits Standby mode in 60 µs when an external reset (NRST pin), an IWDG
reset, a rising edge on one of the three WKUP pins, RTC alarm (Alarm A or Alarm B),
RTC tamper event, RTC timestamp event or RTC Wakeup event occurs.
•
Standby mode without RTC
The Standby mode is used to achieve the lowest power consumption. The internal
voltage regulator is switched off so that the entire VCORE domain is powered off. The
PLL, MSI RC, HSI and LSI RC, HSE and LSE crystal oscillators are also switched off.
After entering Standby mode, the RAM and register contents are lost except for
registers in the Standby circuitry (wakeup logic, IWDG, RTC, LSI, LSE Crystal 32 KHz
oscillator, RCC_CSR register).
The device exits Standby mode in 60 µs when an external reset (NRST pin) or a rising
edge on one of the three WKUP pin occurs.
Note:
The RTC, the IWDG, and the corresponding clock sources are not stopped automatically by
entering Stop or Standby mode.
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Functional overview
STM32L052x6 STM32L052x8
Table 3. Functionalities depending on the operating power supply range
Functionalities depending on the operating power supply
range
Operating power supply
range(1)
DAC and ADC
operation
Dynamic voltage
scaling range
USB
VDD = 1.65 to 1.71 V
ADC only, conversion
time up to 570 ksps
Range 2 or
range 3
Not functional
VDD = 1.71 to 1.8 V(2)
ADC only, conversion
time up to 1.14 Msps
Range 1, range 2 or
range 3
Functional(3)
VDD = 1.8 to 2.0 V(2)
Conversion time up to
1.14 Msps
Range1, range 2 or
range 3
Functional(3)
VDD = 2.0 to 2.4 V
Conversion time up to
1.14 Msps
Range 1, range 2 or
range 3
Functional(3)
VDD = 2.4 to 3.6 V
Conversion time up to
1.14 Msps
Range 1, range 2 or
range 3
Functional(3)
1. GPIO speed depends on VDD voltage range. Refer to Table 61: I/O AC characteristics for more information
about I/O speed.
2. CPU frequency changes from initial to final must respect "fcpu initial