Adding a companion chip to a low-voltage host processor can create quite a challenge for designers. STMicroelectronics addressed that issue with its STM32 microcontrollers (MCUs)—they connect to the same digital power domain as the host (e.g., a 1.8-V power supply) while allowing on-chip peripherals to operate from higher voltages, such as 3.3 V. The STM32F038/48/58/78 and STM32F318/28/58/78 low-voltage MCUs also enable flexible design partitioning. This is particularly comes to the fore when the need arises for a wide analog dynamic range, or when connecting directly to USB devices. The STM32F0x8 I/Os make it possible to bridge between different voltages without using level shifters. Meanwhile, the analog-to-digital converter (ADC) peripheral of the STM32F3x8 devices is fully functional down to 1.8 V. The STM32F0x8 MCUs combine an ARM Cortex-M0 core with up to 128 kbytes of on-chip flash; the STM32F3x8s, based on the ARM Cortex-M4 with DSP instruction set and floating-point unit, offer up to 512 kbytes of flash. Packaging styles include low-profile CSP, UQFN, and UFBGA, as well as TSSOP and LQFP. Pin configurations range from 20 to 100.