TPIC7218-Q1: GMR abnormal output

Hi Expert, 

Something wrong with the GMR output. The battery voltage is 12V, the GMR voltage will drop down to 14.2V from 23V after power on, the GPR and CHP will be always 23V. 

Urgent case, please give me a hand asap! 

Thanks a lot! 

Andy 

The waveform and schematic are in the attachment file.    

Waveform and schematic.docx

Johnsin Tao：

Hi

     建议你将这个问题放到美国E2E:  https://e2e.ti.com/

     这个芯片控制比较复杂，我这边主要熟悉电源控制，而TPIC7218-Q1更多的的配置，我这边资料非常少。