# Tagged Questions

2answers
426 views

### Wilson current mirror

I built a super wilson current current mirror. The Iin is 4-20mA at 24Vdc. Iin to Iout accuracy was a really bad 5%. I put 100 ohm resisters on the source to ground, and that helped a little. How can ...
1answer
131 views

### What is the dependency of the gate leakage current and the gate voltage?

If I connect the source and the drain of an N-channel power Mosfet to ground and sweep the gate voltage from 0 to U_max. What curve will I see for the gate current in dependency of the gate voltage? ...
2answers
689 views

### Why so many pins for the MOSFET's drain?

The FDC855N comes in a 6-pin package, 4 of which are connected to the drain, and only 1 to the source. Why this difference? The source sees the same current as the drain, doesn't it?
6answers
2k views

### MOSFET: When can we not assume that the gate current is 0?

A common rule of thumb you hear when learning Electrical Engineering is that the gate current of a MOSFET is always approximately 0. When is it not safe to assume that it is 0?
4answers
452 views

### Can the Ids equation of MOSFETs be applied to real devices?

In my engineering course, we have studied MOSFETs a lot, and always in the context of integrated circuits. And what we have been teached is that (in the basic approximation), its current is given by ...
2answers
744 views

### Simple circuit to limit current through a FET

I am looking for a simple circuit which can be used to limit the current flowing through a FET. There is a bus line which is pulled up to the battery voltage (12V) by a 510$\Omega$ resistor. A FET ...
2answers
444 views

### Transistor in saturation mode?

I was wondering why do we so often want out transistor to work in saturation mode? Ie. For a MOS Current Steering Circuit we want our transistors to operate in the saturation region....
1answer
258 views

### Need help understanding and interpreting IGBT datasheets

When it comes to motor control, I understand that we have the option of using discrete MOSFETs or IGBTs. Also, there are some products in the market where 6 IGBTs are placed in one single package, ...