E
Guest
Mon Aug 23, 2010 6:04 pm
I used IPP05N03 from Infineon (30 V, 5 milliohm, TO220)
It avalanches about 39 V at 1,3 Amps and 43 V at 2,3 Amps.
Initially the voltage is volt or so higher but drops in few hours
See graph:
http://koti.mbnet.fi/hsahko/fetzener/data.pdf
Time is in tens of seconds, I have better things to do
than fight with OpenOffice. (12117=33.7 hours)
-ek
legg
Guest
Tue Aug 24, 2010 12:20 am
On Mon, 23 Aug 2010 20:04:25 +0300, "E" <invalid_at_invalid.invalid>
wrote:
Quote:
I used IPP05N03 from Infineon (30 V, 5 milliohm, TO220)
It avalanches about 39 V at 1,3 Amps and 43 V at 2,3 Amps.
Initially the voltage is volt or so higher but drops in few hours
See graph:
http://koti.mbnet.fi/hsahko/fetzener/data.pdf
Time is in tens of seconds, I have better things to do
than fight with OpenOffice. (12117=33.7 hours)
-ek
You'd get more predictable performance by placing a proper zener
between drain and gate, with a suitable gate shunt resistor for zener
biasing.
The mosfet has better energy handling characteristics when not in
avalanche.
RL
E
Guest
Tue Aug 24, 2010 8:22 am
"legg" <legg_at_nospam.magma.ca> kirjoitti
viestissä:4c06765vauv2v337uehhbj35flnsb1a1vh_at_4ax.com...
Quote:
On Mon, 23 Aug 2010 20:04:25 +0300, "E" <invalid_at_invalid.invalid
wrote:
I used IPP05N03 from Infineon (30 V, 5 milliohm, TO220)
It avalanches about 39 V at 1,3 Amps and 43 V at 2,3 Amps.
Initially the voltage is volt or so higher but drops in few hours
See graph:
http://koti.mbnet.fi/hsahko/fetzener/data.pdf
Time is in tens of seconds, I have better things to do
than fight with OpenOffice. (12117=33.7 hours)
-ek
You'd get more predictable performance by placing a proper zener
between drain and gate, with a suitable gate shunt resistor for zener
biasing.
Yes, the avalanche voltage is not too precise
Quote:
The mosfet has better energy handling characteristics when not in
avalanche.
This is the more interesting part: It is actually just the other way!
I tried that zener (27 V) + resistor (1k) circuit, and it turns into
a short circuit at about 50 W dissipation. 50 W at 30 V is way out
of SOA
Datasheet:
http://koti.mbnet.fi/hsahko/fetzener/IPP05N03LB.pdf
If the gate is grounded, then it can dissipate 100 W @ 43 V no problem
I assume that at 100 W dissipation the die in a TO220 package is near
max temp.
-ek
legg
Guest
Mon Aug 30, 2010 4:25 am
On Tue, 24 Aug 2010 10:22:41 +0300, "E" <invalid_at_invalid.invalid>
wrote:
Quote:
"legg" <legg_at_nospam.magma.ca> kirjoitti
viestissä:4c06765vauv2v337uehhbj35flnsb1a1vh_at_4ax.com...
On Mon, 23 Aug 2010 20:04:25 +0300, "E" <invalid_at_invalid.invalid
wrote:
I used IPP05N03 from Infineon (30 V, 5 milliohm, TO220)
It avalanches about 39 V at 1,3 Amps and 43 V at 2,3 Amps.
Initially the voltage is volt or so higher but drops in few hours
See graph:
http://koti.mbnet.fi/hsahko/fetzener/data.pdf
Time is in tens of seconds, I have better things to do
than fight with OpenOffice. (12117=33.7 hours)
snip
The mosfet has better energy handling characteristics when not in
avalanche.
This is the more interesting part: It is actually just the other way!
I tried that zener (27 V) + resistor (1k) circuit, and it turns into
a short circuit at about 50 W dissipation. 50 W at 30 V is way out
of SOA
Datasheet:
http://koti.mbnet.fi/hsahko/fetzener/IPP05N03LB.pdf
If the gate is grounded, then it can dissipate 100 W @ 43 V no problem
I assume that at 100 W dissipation the die in a TO220 package is near
max temp.
-ek
I'm unaware of any record of mosfet avalanche testing that would agree
with your findings.
Have you scoped voltage and current waveforms during avalanche? Some
metering is highly susceptible to the emi that accompanies avalanche
or even improperly-biased controlled zenering.
I have one meter that can even be convinced to flash it's low battery
indicator, if unproperly screened in such a test set-up. Under no
circumstances trust internal shunt readings of meters with long leads.
RL
