Re: 4420 driver ICs

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 31 Mar 2004, at 17:38, Tesla list wrote:

 > Original poster: Fucian-at-aol-dot-com
 >
 > Hey,
 > Ive been having weird trouble with my 4420 fbsstc...They keep dying,
 > for no apparent reason...I just had one die once i put the circuit
 > into a grounded metal enclousre...It just stays on w/o even having a
 > signal to turn it on...Another died after not having ANYTHING done to
 > it...It worked the night before, i turned it on today, absolutlely
 > nothing...ANother just decided to give 1cm sparks reguardless of the
 > power i gave it...Frequcny was measured at 60hz?

Question: are the inputs essentially FET gates? They may hold a
charge which could turn them on the moment the supply rails are
powered-up if the inputs are not connected to anything. Static
sensitivity might also be a problem if they are mishandled.

Malcolm



 > So i need to buy, alot of these...Maybe samples are crappy quality and
 > fail quickly?I had 1n60 diodes to protect it, they check finel...I
 > tried mouser, but they just didnt even respond even though i used my
 > credit card and got 10 of them...No repsonse from them..digikey wants
 > alot of $$$ and the other main places want me to buy 60min...
 >
 > Does anyone here have any to sell me?
 >
 > Matt
 >
 >
 >