72 MHz Cortex-M3 with 384 KB Flash in a 144-BGA
It is built for real-time control applications that need a rich peripheral set: dual 12-bit ADCs (21 channels), dual 12-bit DACs, motor-control PWM timers, DMA, CAN, USB, and multiple UART/SPI/I²C interfaces.
The supply range of 2.0 V to 3.6 V gives headroom for 3.3 V or battery-backed 2.5 V rails, with the internal POR/PVD monitoring the supply for brown-out events. The BGA package's thermal characteristics are adequate for the 72 MHz core at industrial temperature, but the 10x10 mm array needs a well-vented PCB stack and proper solder-joint inspection during assembly.
It is currently in volume production with no announced end-of-life or last-time-buy schedule. The base product number STM32F103 spans multiple density and package variants, so a pin-compatible migration path exists within the family if future capacity needs shift.
Peripheral set: CAN, USB, and motor-control PWM
The on-chip peripherals include a CAN 2.0B interface for industrial fieldbus, a full-speed USB 2.0 device port, and a motor-control PWM timer with complementary outputs and dead-time insertion — features that target brushless DC motor drives and servo controllers. DMA offloads the Cortex-M3 core during high-speed ADC conversions or UART data streaming, so the 72 MHz throughput is not wasted on interrupt overhead. The 21-channel 12-bit ADC can sample at 1 µs per channel, adequate for current-sense and position-feedback loops in motor drives.
Flash and RAM budget — firmware sizing
With 384 KB of Flash, the firmware image can include a real-time OS kernel, CANopen or Modbus stacks, USB device firmware, and a modest application layer. The 64 KB SRAM is shared between stack, heap, and DMA buffers — enough for a single CAN message buffer pool and a few kilobyte USB endpoint buffer, but tight if the design requires large image processing or extensive data logging. For applications that need more volatile memory, an external SRAM or SDRAM can be added via the FSMC interface (not present on all STM32F103 packages; verify the ZDH6 variant's FSMC availability in the reference manual).