36 MHz — the speed trade-off in the STM32F1 line
The 36 MHz core clock is the deliberate ceiling that differentiates the STM32F101 from the STM32F103 series (which runs at 72 MHz). If your application needs faster ADC sampling, tighter PWM resolution, or higher throughput on the serial buses, the STM32F103VCT6 is the pin-compatible upgrade — same 100-LQFP footprint, same memory map, same peripheral set, just double the clock and a USB interface. For control loops that can close at 36 MHz or for designs where the extra MHz would be unused headroom, the F101 saves BOM cost without changing the board layout.
100-LQFP — field-swappable package
It is reworkable with a hot-air station or a standard reflow profile, and the pin pitch is wide enough that a technician can hand-solder a replacement in the field with a fine-tip iron — no BGA underfill or X-ray inspection needed.