This application provides a circuit and
system for
voltage information diagnosis and self-calibration. By adding resistors R1 and R2 in series, the
total cell voltage is divided, reducing the sampling point
voltage Vsample to the measurement range of the analog-to-
digital converter (ADC) of the
microcontroller (MCU). The MCU accumulates and calculates the total voltage Vafe by sampling the voltages of each
cell from the analog front-end (AFE). Based on the Vafe data from the AFE, the
total cell voltage Vmcu is automatically calibrated to obtain the calibrated
total cell voltage Vcalib. Simultaneously, the MCU compares the calibrated total
cell voltage Vcalib with the Vafe voltage in real time to obtain the deviation value Vdiag. When the deviation value Vdiag exceeds a set threshold, fault diagnosis is triggered, indicating an
abnormality in the
cell voltage sampling function, and a safety
protection mechanism is activated to meet
functional safety requirements. This circuit, through reasonable hardware design, voltage protection, cell total voltage calibration, and fault diagnosis mechanism, not only improves the accuracy of
system measurements but also achieves self-calibration and fault diagnosis, making it suitable for applications with high stability requirements.