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Fail shunt regulator, 431, in ESD test?

B

Bob J.

Jan 1, 1970
0
Hi, all,

Shunt regultor, 431, is failure during testing Electrostatic
discharge(ESD). The testing conditon is 10 times 8KV in contact and 10
times 15KV in air.

I think clearance is short between Vout and 431 on PCB. However, it is
not enough to explain and report.

So, let me know why it is happen and what I should do not for happening
again in the future.

You can see the part of circuit and PCB below.

http://my.dreamwiz.com/jyeonsuk/2004_new/questions/esd/with_431_large.html

Thanks.

Bob,
 
P

Pooh Bear

Jan 1, 1970
0
Bob J. said:
Hi, all,

Shunt regultor, 431, is failure during testing Electrostatic
discharge(ESD). The testing conditon is 10 times 8KV in contact and 10
times 15KV in air.

I think clearance is short between Vout and 431 on PCB. However, it is
not enough to explain and report.

So, let me know why it is happen and what I should do not for happening
again in the future.

You can see the part of circuit and PCB below.

http://my.dreamwiz.com/jyeonsuk/2004_new/questions/esd/with_431_large.html

Is someone actually applying the ESD test directly to a connector pin ? I'm
not surprised it's failing.

Graham
 
B

Ban

Jan 1, 1970
0
Bob said:
Hi, all,

Shunt regultor, 431, is failure during testing Electrostatic
discharge(ESD). The testing conditon is 10 times 8KV in contact and 10
times 15KV in air.

I think clearance is short between Vout and 431 on PCB. However, it is
not enough to explain and report.

So, let me know why it is happen and what I should do not for
happening again in the future.

You can see the part of circuit and PCB below.

http://my.dreamwiz.com/jyeonsuk/2004_new/questions/esd/with_431_large.html

Thanks.

Bob,

Look at the datasheet Absolute Maximum Ratings:
Reference Input Current Range IREF -0.05 ~ +10 mA

this means you have to avoid *any* negative voltage there above a diode
drop. You should clamp that with a Schottky diode on this point or else a
7V5 zener , which would also help with the positive part of the puls.
 
J

John Fields

Jan 1, 1970
0
Hi, all,

Shunt regultor, 431, is failure during testing Electrostatic
discharge(ESD). The testing conditon is 10 times 8KV in contact and 10
times 15KV in air.

I think clearance is short between Vout and 431 on PCB. However, it is
not enough to explain and report.

So, let me know why it is happen and what I should do not for happening
again in the future.

You can see the part of circuit and PCB below.

http://my.dreamwiz.com/jyeonsuk/2004_new/questions/esd/with_431_large.html
 
B

Bob J.

Jan 1, 1970
0
Hi, John Fields,

Let me know the TVS, please.

Bob.
 
P

Pooh Bear

Jan 1, 1970
0
Bob J. said:
Hi, John Fields,

Let me know the TVS, please.

I see you're looking for a 'band aid' fix rather than finding out why
your pcb failed a test on its *enclosure* !

Graham
 
T

Terry Given

Jan 1, 1970
0
Bob said:
Hi, John Fields,

Let me know the TVS, please.

Bob.

Ye Gods, how much help do you need? RTFPs

Cheers
Terry
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Pooh Bear
I'll venture he can't decrypt the acronym.

Wot's an acronym? I no wot decrypt is; my grandmother's decrypt. She
can't walk.
 
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