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BQ76952: BQ76952短路时RST_Shut有1.24V干扰电压

Part Number: BQ76952

应用原理描述:应用BQ76952的DDSG和DCHG做低压驱动隔离芯片,进而控制高端的充放电MOS

测试异常问题:做P+、P-短路的时候,由于layout的原因,BQ76952会有1.24V的干扰电压,持续时间100us,这种情况会导致DDSG短路保护后重新开启多次(间隔几个ms),进而损坏Fuse。

但在RST_SHUT端口增加电容把干扰电压滤掉,短路时DDSG正常保护且后面不会再次开启。

沟通记录:我把这种情况反馈到TI FAE的BU,他们根据我们描述的做了一样的测试,发现出现了跟我们一样的现象,DDSG短路立即保护,后面又会重新开启,只是时间稍有差别。

疑问点1:规格书描述和现象的差异可以对此原因进行澄清吗?

从现象上看RST_SHUT有干扰电压确实会清掉保护重新开启DDSG,但看规格书描述短时间复位不会立即清掉保护状态,如下:"When the pin is driven high, the device will immediately reset most of the digital logic, including that associated with the serial communications bus. However, it does not reset the logic that holds the state of the protection FETs and FUSE, these remain as they were before the pin was driven high."

疑问点2:短时间RST_SHUT复位之后DDSG重新开启是芯片特性还是受配置影响?

疑问点3:短时间RST_SHUT复位会清掉哪些状态?