6
votes
Accepted
MOSFETs stabilizing current in coils keeps burning, how to protect them?
The thermal resistance of the MOSFET junction-case interface, compared with the thermal capacity, coupled with thermal runaway, makes it very easy to burn out these device before the case even gets ...
- 6,301
4
votes
Production quality issue?
My reaction would be contingent on the type of failure encountered.
As you mentioned, these failure rates might be acceptable in hobby projects, but they are certainly not suitable for professional ...
- 3,226
2
votes
How to understand current limiter circuit
Current to the load flows through R1 and M1. As load current increases, the voltage difference across R1 increases, which raises Q1's emitter voltage relative to the base (Veb rises), which "...
- 16.4k
2
votes
DC-DC buck converter's MOSFET or IGBT?
Quick answer:
SiC MOSFETs would be better than IGBTs for efficiency, but may result in higher cost, depending on whether the benefits of SiC (specifically higher switching frequency for a given power ...
- 1,791
2
votes
How to derive thermal time constant from a MOSFET's datasheet?
Vishay didn't link this to the FET but they offer a separate datasheet for the thermal characterstics here. i found all the information I need.
I guess another approach would be to use a curve fitting ...
- 105
1
vote
How to understand current limiter circuit
Working of circuit ... Made with microcap v12.
Internal output impedance is rather high, something like 1.1 Ohm.
- 12k
1
vote
N channel MOSFET as high side switch
A simple solution is to use photovoltaic driver, like VOM1271, from Vishay.
You need to supply 10 mA to the diode, from 24 V or any output, and typical open circuit voltage is 8.4 V, but only 15 uA. ...
- 1,334
1
vote
Accepted
Automotive MOSFET active clamping circuit - LC ringing between coil load and MOSFET gate?
Try an R+C from drain to source. Exact values depend on cable length, solenoid impedance, etc., but typical values would be \$C \ge 3 C_\textrm{oss}\$ and \$R = \sqrt{L \,/\, C_\textrm{oss}}\$, or ...
- 27.6k
1
vote
Accepted
Why are MOSFETs called voltage controlled devices even though we have to push in charge/current to charge the input capacitances?
The voltage between gate and source is what is controlling the conductivity of the channel. It is the electrical field, not a current that has influence.
Yes, every FET has some specific gate ...
- 9,469
1
vote
MOSFETs stabilizing current in coils keeps burning, how to protect them?
Noting that:
I'd expect that your PID controller will not make any very fast gate voltage swings during normal operation, but may at turn on and off.
It's not clear if damage occurs during PID ...
- 149k
1
vote
Reducing the fall-time of a P-channel MOSFET
Here is a modified circuit:
I didn't use the exact MOSFET model. The one you are using has a lot of gate charge. Also note the absolute maximum Vgs is 20V, but that's typical of such parts.
Here is ...
- 385k
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