BQ24450 meaning of parameter Vpre_rev?

Thread Starter

Timo D.

Joined Oct 21, 2011
3
Hi all,

this is maybe a silly question but I'm really not sure about this:
The BQ24450 spec (same as UC3906) states a parameter called
Vpre_rev: PRE-CHG reverse hold-off voltage
For UC3906 it's called trickle bias reverse hold-off voltage.

Now, what's the difference between that and the max. rated
reverse voltage at PRE-CHG/trickle bias pin?
I mean, if I could only apply up to 7V at this pin it would damage
the device as soon as I remove Vin and have a e.g. 12V battery
still attached. But this is how I understand this spec.

Thanks in advance,
Timo
 

Thread Starter

Timo D.

Joined Oct 21, 2011
3
OK, let me summarize it:

The max. rating states Vin-(PRE-CHG) = -32V

Operation spec is:
PRE-CHG (with Vin=0V, Ipre=-10uA) = 7V max.

Does this simply mean that I have to assume a
current much more than 10uA if I apply up to 32V
at PRE-CHG, but the pin would withstand that?

So adding Dext would solve both, minimum Ipre current
at VBat > 7V?

Thanks,
Timo
 
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