Can a 1.5KE series TVS be used as a zener with a dC bias.
Sat I have a circuit that is fed by a 50mA current source that on fault conditions pulses up to 500mA for ~10mS.
The circuit needs to clamp at between 33 and 40V. I have a 36V 1.5KE already in the circuit for transient protection of a 30V line elsewhere but was wondering if I could use the same part for this zener application.
Don't see why not :)
Grant.
Sure. Read the transzorb data sheet, especially the curves. A Vishay
1.5KE36 has a min/max drop of 32.4/39.6 at 1 mA, so it's close to what you need. The "A" version is tighter.A transzorb is just a big sloppy zener. Except the bidirectional ones are two big zeners.
John
I've been told a significant difference is that transzorbs are generally designed to fail short-circuit whereas one typically expects a Zener to fail open-circuit...
I've popped a few different zeners and they fail shorted every time unless I have enough juice to bend the leads the opposite way they were installed. :)
I suspect if it failed to short circuit, the failure would be temporary...
Yup. Any diode will fail open if you have the right number of amps available.
John
ge
ail
I would want my zener to fail short-circuit, if I have a choice.
Right, the idea (it was explained to me) is that they're first short and then remain shorted long enough (assuming you've sized it correctly) to blow the in-line fuse.
then
he
Correct, I spec my zener: 30W-NO, 50W-SC, 1MW-OC
(NO: Normal Operation, MW: MegaWatt)
Yup, they achieve proper zener voltage just one more time. For a few picosecond ... *PHOOMP*
Have something to add? Share your thoughts — no account required.
Ask the community — no account required