damage after metal fusing

[Jinkyu]

Have you ever experience damage after fusing.
Fusing condition is 300mA for 6mS.
The damage shows as vno and psrr in terms of AC characteristic.
Do you have any idea for fusing circuit to prohibit damage?

 

[goldsmith]

Dear Jinkyu
Hi
What do you mean accurately? do you want to keep your circuit from high currents with fuse ? is your problem , that your voltage is square wave?
Best Wishes
Goldsmith

 

[dick_freebird]

A flyback voltage excursion can do hot carrier or breakdown
damage.

On ATE / probe setups there is a good chance that a current-
mode blow will have a significant flyback when the fuse opens.
Voltage-mode programming is my preference, with the power
connect by relay.

However the foundry specifies a blow-condition under which
the fuse is guaranteed reliable, and deviations cost you that
"coverage". You might consider adding a transient voltage
supression (boosted zener, for example) that prevents the
current from going pin-overvoltage and punching out the FET.
In cases such as you show, the FET may be a high voltage drain
type operated inverted, so the source has high blocking ability.
But this makes an inferior source-follower (series resistance of
extended / DMOS drain).

I also prefer the fuses to be in low power switch cells and
any current carrying, performed by FETs. The resistance
and capacitance are inferior, but the fuse is segregated
from critical active and especially pad-exposed circuitry.