[SOLVED] Battery Protection IC Problem

[shaq]

Dear all,
The link of shown below is the battery protection IC with integrated power-mos by ALPHA company.
**broken link removed**

In page 1, it's written "Charger connection pin withstands up to 28V."

I have two problems on block diagram of page 4.

1) If 28V-charger is connected, EB-=VM=26V when VCC=2.0V.
Why the three comparators which are discharge over-current comp, charge over-current comp and short-circuit comp cannot be damaged?

2) Can someone tell me what kind of high voltage process can be used?

 

[erikl]

... In page 1, it's written "Charger connection pin withstands up to 28V."

28V seems to be a max. voltage "standard" for dumb low voltage mains adapters. This 28V event has only a short duration until the adaptor provides current. That's why a lot of accumulator charger ICs have to stand this rating, s. e.g. ISL9214/9221 from Intersil.

1) If 28V-charger is connected, EB-=VM=26V when VCC=2.0V.
Why the three comparators which are discharge over-current comp, charge over-current comp and short-circuit comp cannot be damaged?

During such an overvoltage event, the IC will not be in normal operation. Via R2 and the internal ESD protection, the VM node is protected against the 28V event.

2) Can someone tell me what kind of high voltage process can be used?

Several foundries offer standard CMOS processes with LD (lateral diffused) drain MOSFETs which are able to stand such high voltages, e.g. AMS, IBM, Tower, TSMC and more, s. e.g. the PDFs below.