From: Winfield Hill
Subject: Re: Problems with MOSFET drivers
Date: 16 Nov 2002 18:16:29 -0800
Organization: Rowland Institute
X-Newsreader: Direct Read News 4.10
> Eric Y. Chang wrote
>> Adam Seychell (firstname.lastname@example.org) wrote:
>>: * get access to >= 60MHz CRO if you hanv't done so already.
>> And look for what? Gloat rights on owning a fast oscilloscope.
Sheesh! He shouldn't just have a fast scope, but a also set of high-
frequency high-voltage differential probes, even if he has to make
them himself. Plus a set of high-frequency current probes. These
are your eyes. One does not prefer to be blind.
>> First, one should ask why 9A drivers are being destroyed. Yes, the
>> data sheets say that they are bulletproof, but obviously they are
>> not. When a device rated for 9A violently explodes, the cause is
>> usually overcurrent. The overcurrent can be stopped by a "fuse."
> Dear God. If the overcurrent is caused by destructive breakdown,
> then device itself may have already acted as the 'fuse', putting an
> external fuse in will do nothing other than waste money on fuses.
I completely agree, an IC experiencing improper voltages, or high
substrate currents, etc. will blow faster than an instrument fuse.
The solutions include 1) knowledge and understanding, 2) analysis
and 3) measurement (reduced voltages are suggested, approaching the
trouble region slowly), and sadly probably not fuses. Sorry. :)