J
Joerg
Fred said:Joerg a écrit :
Diodes' SOT363 HBDM60V600W or MMDT5451 and 2 x 0402/0201 resistors ?
Yeah, if I have to ... thing is, most contract mfgs shy away from 0201
and then you have to use 0402.
Fred said:Joerg a écrit :
Diodes' SOT363 HBDM60V600W or MMDT5451 and 2 x 0402/0201 resistors ?
Yeah, if I have to ... thing is, most contract mfgs shy away from 0201
and then you have to use 0402.
Spehro said:For this sort of thing I almost always use networks rather than
individual resistors. Considerably less space and less mounting cost
at very little additional parts cost.
For this sort of thing I almost always use networks rather than
individual resistors. Considerably less space and less mounting cost
at very little additional parts cost.
Jim said:If it's "extinguished" does the rail stay on? This implies original
triggering was due to the "desired" dv/dt?
Only shallow thinkers have "several mA wasting away all day long" ;-)
Jim said:Specs? I know that's a naughty word around here. Minimum dv/dt
required to trigger. Further definition of 'extra 'regular" trigger'?
"Un"trigger specs?
Ok, to save on space, how about using a GTO ? ETO's would work butJoerg said:Actually in this case dv/dt is even desired
It's supposed to come on when a voltage rail comes on and then remain
on, unless a uC deliberately "extinguishes" it but briefly shunting a
FET across the SCR.
I just can't have several mA wasting away all day long.
why not use a sol single package type RS flip flip to drive an openJoerg said:That would deplete the battery. There are periods of time where the load
draws very little and I can't have the SCR path burn off power that
whole time.
V can be up to 60V and I should be <1mA.
Jamie said:why not use a sol single package type RS flip flip to drive an open
Drain higher voltage Nmos?
It almost appears to me that you are doing a design that does not
involve a uP ?
I've done such cheap designs using a 555 timer but only for its trigger
and threshold latches to control a device. The trigger snapped it on and
threshold input turned it off. It also works well for a ripple detector
in circuits where rush currents or voltages need to be acted on.
Jamie said:Ok, to save on space, how about using a GTO ? ETO's would work but
I find them mostly in large applications.
At least with a GTO, if you keep the gate voltage in the on state,
it'll keep the device switched in at low currents. Unless you have a
pulse transformer in there?
In any case, this could remove your need for the shunting fet and free
up some space to maybe enhance the GTO operation.
You can make the holding current as small as you want by injecting a bias current into the gate.
As long as you want to keep the CONTEXT a big mystery, you're not gonna get a reasonable answer.
That is a good idea. If I can find uses for the remaining resistors in
there as pull-ups or something.
Spehro said:There are 1mm x 1mm 2-resistor networks. No leftovers.
Tim said:Can you make one with "high voltage" JFETs? Maybe you can find some
with 60Vds (most are 30). Minimum turn on threshold may be too low,
don't think you mentioned minimum supply requirement. Of course, the
canonical structure would use a PFET, but you could substitute a PNP so
you only need half the resistors, or something like that.
MOS is similarly an option if you can find one with really high
Vgs(max). Unlikely..
Those would be nice. But I am afraid they won't want anything smaller
than 0402 in terms of pitch.
Can you make one with "high voltage" JFETs? Maybe you can find some
with 60Vds (most are 30). Minimum turn on threshold may be too low,
don't think you mentioned minimum supply requirement. Of course, the
canonical structure would use a PFET, but you could substitute a PNP so
you only need half the resistors, or something like that.
MOS is similarly an option if you can find one with really high
Vgs(max). Unlikely..
Typical Joerg ;-)
What's with the Outhouse Excuse style punctuation?
Aren't two resistor 0402 (metric 1005) arrays (metric 1010) 1x1mm?