TSMC025 BCD工艺(±12V)中要求LV device region must be surrounded by HVPW and P+ isolation ring,
并且要求P+ isolation ring must be connected to the most negative voltage
这里讲的most negative voltage是-12V吗?
字面意思看起来像是-12V但是如果接-12V的话LV region的psub(0V)就会与这个HVPW and P+ isolation ring存在softconnect问题
为避免这个softconnect造成的softchk问题只能让这个HVPW and P+ isolation ring去接0V