MAX1044, Static Damage?
Posted: 10 Aug 2007, 23:21
Over at the other forum, some people were complaining that their MAX1044 charge pump chips had failed. Several of them had come to the conclusion that it must be caused by too much voltage as it's only designed to run on 10v. But I honestly don't see how that can be a serious issue if it runs on a 9v battery. I've never measured a 9v to be anywhere near 10v and most of the time, they are considerably less than 9v, so I think the problem lies elsewhere.
Specifically, I believe the chips are failing due to ESD damage. I hypothesize that a likely unprotected part of the where static could damage the chip would be at the battery clip. According to the functional diagram in the datasheet, the V+ pin connects to a MOSFET switch inside the chip that's part of the charge/discharge circuit. Without protection on the V+ input, I believe it could be very easy for damaging static discharges to enter into the chip and damage the MOSFET switches. And I believe that this is what has been happening to people's chips "in the field".
I encourage others here to help enlighten us on this subject. Does this seem like a plausible explanation for the problem? What would you recommend as a good protection scheme? A zener diode?
I tried to bring this concept up at the other forum, but it seems to have been completely ignored (as usual), so I wish to continue the discussion here.
Specifically, I believe the chips are failing due to ESD damage. I hypothesize that a likely unprotected part of the where static could damage the chip would be at the battery clip. According to the functional diagram in the datasheet, the V+ pin connects to a MOSFET switch inside the chip that's part of the charge/discharge circuit. Without protection on the V+ input, I believe it could be very easy for damaging static discharges to enter into the chip and damage the MOSFET switches. And I believe that this is what has been happening to people's chips "in the field".
I encourage others here to help enlighten us on this subject. Does this seem like a plausible explanation for the problem? What would you recommend as a good protection scheme? A zener diode?
I tried to bring this concept up at the other forum, but it seems to have been completely ignored (as usual), so I wish to continue the discussion here.