ARM-Based MCUs Support Crystal-Less USB Design
STMicroelectronics’ STM32F0x2 microcontroller family, based on the ARM Cortex-M0 core, supports CAN and integrates a full-speed USB 2.0 controller with a self-calibrated clock system to simplify design. The 12-Mbit/s USB 2.0 interface has its own 48-MHz oscillator. Beyond USB 2.0, there’s support for USART, I2C, I2S, HDMI CEC, and ISO 7816. Other USB functionality includes battery-charger detection that allows battery-powered devices to optimize recharging times, and link-power management that helps save energy via enhanced system control. Separate power domains for analog and digital I/Os support low-voltage operation and allow for a higher voltage dynamic range for accurate sensing on analog peripherals. Main supply voltage ranges from 2.0 to 3.6 V. Among the power-management modes available are USB SUSPEND, STOP (reduces current to 5 µA and has a 4.2-µs wakeup time), and STANDBY (2.5 µA). The MCUs provide 16 to 128 kbytes of flash memory in 20- to 100-pin packages. Packaging options include TSSOP, LQFP, UFQFPN, UFBGA, WLCSP, or die form. Applications include communication gateways, smart-energy devices, Internet of Things, and consumer electronics (smartphones, game terminals).