The sampling and multiplexing trigger can be controlled from a variety of sources including timers and built-in comparators, allowing for irregular sampling intervals where needed. The op-amps inputs feature 2-to-1 analog multiplexer, allowing for a total of eight analog channels to be pre-processed using the op-amp; all the op-amp outputs can be internally connected to ADCs. STM32 F2 The STM32 F2-series of STM32 microcontrollers based on the ARM Cortex-M3 core. It is the most recent and fastest Cortex-M3 series. The F2 is pin-to-pin compatible with the STM32 F4-series. The summary for this series is: Core: ARM Cortex-M3 core at a maximum clock rate of 120 MHz. Memory: Static RAM consists of 64 / 96 / 128 KB general purpose, 4 KB battery-backed, 80 bytes battery-backed with tamper-detection erase. Flash consists of 128 / 256 / 512 / 768 / 1024 KB general purpose, 30 KB system boot, 512 bytes one-time programmable (OTP), 16 option bytes. Each chip has a factory-programmed 96-bit unique device identifier number. Peripherals: Common peripherals included in all IC packages are USB 2.0 OTG HS, two CAN 2.0B, one SPI + two SPI or I²S, three I²C, four USART, two UART, SDIO/MMC, twelve 16-bit timers, two 32-bit timers, two watchdog timers, temperature sensor, 16 or 24 channels into three ADCs, two DACs, 51 to 140 GPIOs, sixteen DMA, real-time clock (RTC), cyclic redundancy check (CRC) engine, random number generator (RNG) engine. Larger IC packages add 8/16-bit external memory bus capabilities. The STM32F2x7 models add Ethernet MAC, camera interface, USB 2.0 OTG FS. The STM32F21x models add a cryptographic processor for DES / TDES / AES, and a hash processor for SHA-1 and MD5. Oscillators consists of internal (16 MHz, 32 kHz), optional external (4 to 26 MHz, 32.768 to 1000 kHz). IC packages: WLCSP64, LQFP64, LQFP100, LQFP144, LQFP176, UFBGA176. Operating voltage range is 1.8 to 3.6 volt. STM32 F1 The STM32 F1-series was the first group of STM32 microcontrollers based on the ARM Cortex-M3 core and considered their mainstream ARM microcontrollers. The F1-series has evolved over time by increasing CPU speed, size of internal memory, variety of peripherals. There are five F1 lines: Connectivity (STM32F105/107), Performance (STM32F103), USB Access (STM32F102), Access (STM32F101), Value (STM32F100). The summary for this series is: Core: ARM Cortex-M3 core at a maximum clock rate of 24 / 36 / 48 / 72 MHz. Memory: Static RAM consists of 4 / 6 /