关键词: MCU, 浪涌, TVS管, 热插拔

Abstract: The Customer feedback two pieces of CKS32F030K6T6 as the main control of the motor board can’t drive the motor run normally, and measure the chip power supply pin short circuit. Technical analysis of the faulty circuit board found that the MCU PA7 pin was subjected to abnormal voltage shock, resulting in pin damage and short-circuit to VDD and GND. On-site inspection of the customer's circuit diagram, found that the damaged pin did not do any surge protection. According to the actual application scenario of the customer's circuit, we optimize the test process steps to avoid hot-plugging. At the same time, the MCU pins of the board as ports are connected in series with current-limiting resistors and increase TVS tube protection to reduce the damage of surge voltage on the pins. After the improvement, there is no more surge damage to the pins during the mass production of the customer's board.

Key words: mcu, surge, tvs tubes, hot swapping