Are there any updates for the old and new versions of the STM32L072CZT6?
All the microcontrollers in this comparison test are STM32L072CZT6, and they used the same firmware, PCB, and testing procedures. The test results are as follows:
PCB new batch MCU – UID: 16473531-32333338-003C0041
This is the STM32L072CZT6 from the new batch we received. Without making any changes to the firmware, the LED indicator flashes blue (instead of green), and the current consumption in sleep mode is about 6.44 mA.
Previously manufactured batch MCU – UID: 19513931-30383135-0017004E
The LED flashes green, and the current consumption in sleep mode is about 117.97 µA.
DigiKey STM32L072CZT6 – UID: 04473234-34313430-00160034
This component was purchased directly from DigiKey. The LED flashes green as expected, and the current consumption in sleep mode is about 43.07 µA. The newly supplied components show significant performance differences compared to the reference components obtained from DigiKey.
The difference in sleep current is extremely noticeable: the former is around 6.44 mA, while the latter is only 43.07 µA. Additionally, when running the exact same firmware, we also observed differences in hardware behavior regarding LED pin configuration/mapping. These findings raise serious doubts about whether the newly supplied components are truly equivalent to the original STM32L072CZT6 devices.
Attached photos show the unique IDs read directly via STM32CubeProgrammer, and the attached videos demonstrate the functionality and power measurement results of the devices.
For devices with batch number T-J108W186554A, we observed the same abnormal power consumption issue. Furthermore, we found a serious reliability problem: the device ID stored in the EEPROM may be lost randomly, especially in low-power states. Because this EEPROM issue appears intermittently during testing and requires repeated tests under different power conditions, it is difficult to visually demonstrate this phenomenon through a short video.
