72 MHz Cortex-M3 with 1 MB Flash — the motor-control workhorse
It sits in the STM32F1 series, the de-facto standard for cost-sensitive real-time control in industrial drives, battery chargers, and automation I/O modules. The part packs 112 general-purpose I/O lines, two 12-bit DACs, and a 21-channel 12-bit ADC — enough analog front-end to handle three-phase current sensing plus a thermistor input without external muxing.
Motor-control PWM and DMA — hardware offload for smooth waveforms
The peripheral set includes dedicated motor-control PWM timers and a DMA controller, so the core can generate sinusoidal drive waveforms without cycle-stealing interrupts. For a three-phase PMSM or BLDC motor drive, that means the 72 MHz CPU spends its cycles on the FOC algorithm rather than bit-banging PWM edges. The CANbus interface (2.0B active) handles fieldbus communication to the drive controller, while USB connects to a service tool or charger handshake controller.
144-ball BGA — compact, but plan the reflow profile
The package is a 144-LFBGA measuring 10x10 mm, with a 0.8 mm ball pitch. That is a dense array — 112 I/O plus power and ground balls — so the PCB layout needs at least four layers and microvias or blind vias to fan out the inner rows.