user
An STM32 with at least 128KB of Flash, easy soldering, few pins and low power consumption.
alphonsio

The STM32L412KB MCU may be the best choice

LQFP32 vs UFQFPN32

Here are STM32 microcontrollers that meet your requirements of:

  • At least 128KB of Flash
  • Easy to solder
  • Few pins
  • Low power consumption

In the STM32L family, the L stands for Low Power.

✅ Top Candidates

1. STM32L071KB

  • Flash: 128 KB
  • Package: LQFP32, UFQFPN32 → Easy to solder, few pins
  • Core: Arm Cortex-M0+ @ 32 MHz
  • RAM: 20 KB
  • Low Power: Yes (93 µA/MHz run current)
  • Voltage: 1.65–3.6V
  • Temperature Range: –40°C to 125°C
  • Extras: Secure Boot, Software IP Protection
  • Great for: Battery-powered, cost-sensitive applications

2. STM32L412KB

  • Flash: 128 KB
  • Package: LQFP32, UFQFPN32
  • Core: Arm Cortex-M4 @ 80 MHz with FPU
  • RAM: 40 KB
  • Low Power: Yes (70 µA/MHz run current)
  • Voltage: 1.71–3.6V
  • Extras: USB, Quad SPI, True RNG, Security features
  • Great for: Low-power applications that also need performance and USB support

3. STM32L422KB

  • Flash: 128 KB
  • Package: LQFP32, UFQFPN32
  • Core: Arm Cortex-M4 @ 80 MHz with FPU
  • RAM: 40 KB
  • Low Power: Yes (70 µA/MHz run current)
  • Voltage: 1.71–3.6V
  • Extras: USB, Quad SPI, AES, TRNG, Advanced security features
  • Great for: Secure IoT devices and low-power connected applications

🏆 Best Overall Recommendation

STM32L412KB — offers the best balance of low power, performance (M4 + FPU), small package, and USB capability.

For prototyping, you can buy a Nucleo-32 development board with STM32L412KB MCU that supports Arduino nano connectivity:
Nucleo-32 development board with STM32L412KB MCU