|
Science Forum Index » Electronics Forum » normally-on jfet
Page 1 of 1
|
| Author |
Message |
| sachin |
 Posted: Tue Aug 19, 2003 12:35 pm |
|
|
|
Guest
|
I am sachin.I am doing my research on jfets.
I would like to know how to avoid the start up problems of an normally
on jfet and the applications of jfets.
Please reply me if any one has a answe for this.
sachin. |
|
|
| Back to top |
|
| Robert Baer |
| Posted: Wed Aug 20, 2003 2:34 am |
|
|
|
Guest
|
sachin wrote:
Quote:
I am sachin.I am doing my research on jfets.
I would like to know how to avoid the start up problems of an normally
on jfet and the applications of jfets.
Please reply me if any one has a answe for this.
sachin.
What do you mean "start-up problem"?
What circuit(s) are you having a problem with (describe)? |
|
|
| Back to top |
|
| sachin |
| Posted: Wed Aug 20, 2003 3:36 pm |
|
|
|
Guest
|
Thanks for your reply..
start-up problem in my sense is the large transient current flowing
through the jfet as it is connected to a voltage source..
so i need a solution to avoid this large current in short how to avoid
this short circuit behaviour of jfet.
byee
Robert Baer <robertbaer@earthlink.net> wrote in message news:<3F433351.603E7A46@earthlink.net>...
Quote: sachin wrote:
I am sachin.I am doing my research on jfets.
I would like to know how to avoid the start up problems of an normally
on jfet and the applications of jfets.
Please reply me if any one has a answe for this.
sachin.
What do you mean "start-up problem"?
What circuit(s) are you having a problem with (describe)? |
|
|
| Back to top |
|
| Robert Baer |
| Posted: Wed Aug 20, 2003 11:06 pm |
|
|
|
Guest
|
sachin wrote:
Quote:
Thanks for your reply..
start-up problem in my sense is the large transient current flowing
through the jfet as it is connected to a voltage source..
so i need a solution to avoid this large current in short how to avoid
this short circuit behaviour of jfet.
byee
Robert Baer <robertbaer@earthlink.net> wrote in message news:<3F433351.603E7A46@earthlink.net>...
sachin wrote:
I am sachin.I am doing my research on jfets.
I would like to know how to avoid the start up problems of an normally
on jfet and the applications of jfets.
Please reply me if any one has a answe for this.
sachin.
What do you mean "start-up problem"?
What circuit(s) are you having a problem with (describe)?
Jfets, per se, do *not* act that way, unless you are looking at
transients in the sub-nanosecond region, where capacitance is dominate.
A jfet, with a reasonable Vgs bias (even zero bias) will "pinch off"
above a certain drain to source voltage, making it act like an
adjustable current source (or sink, depending on P or N channel jfet).
A jfet with gate tied to source acts like a linear resistor without
regard to polarity, over a fairly reasonable voltage range.
Changing the Vgs will change that resistivity over orders of magnitude
(down to leakage levels).
Applying a positive bias to the gate will not only decrease that
resistivity, but also may cause significant gate current.
*That* is why i asked about the circuit(s), and i wish to repeat that
question.
Specifics, please.... |
|
|
| Back to top |
|
| |
