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UCD3138: UCD3138 高温上电启动时,电源3.3V被拉低道0V长达80ms以上,PWM有脉冲输出(与软件无关,裸片也有该现象)

Part Number: UCD3138

疫情过后购买的一批UCD3138,用这批UCD3138批量生产的开关电源,在高温上电启动时,电源3.3V被拉低到0V长达80ms以上,这时PWM有脉冲输出,然后再恢复正常工作。有这种问题的芯片大约占25%左右,其他芯片一切正常,请问这个问题怎么解决?

以下是正常UCD3138工作的示波器波形和有问题的示波器波形,黄色为3.3V电源波形,红色和蓝色为PWM波形。

正常波形:

有问题器件波形: