Semiconductors (???????)
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Posts: 46,084
Another semiconductor question: how do the drain, source, and gate on a
MOSFET equate to the base, collector, and emitter on a standard transistor?
Don
>
> Tie the gate to the stamp pin, no resistor is required as the mosfet's
gate
> load is less than a microamp at dc and only a small capacitive load, if
you
> prefer you could use a resistor anything from 470 ohms through 1 meg will
> do. (I personally use a 10K if anything, because I accidentally ordered
ten
> thousand 10,000 ohm resistors).
>
> Tie the drain lead to the relay coil, and put a diode across the coil
> (reverse biased) to limit inductive kickback.
>
MOSFET equate to the base, collector, and emitter on a standard transistor?
Don
>
> Tie the gate to the stamp pin, no resistor is required as the mosfet's
gate
> load is less than a microamp at dc and only a small capacitive load, if
you
> prefer you could use a resistor anything from 470 ohms through 1 meg will
> do. (I personally use a 10K if anything, because I accidentally ordered
ten
> thousand 10,000 ohm resistors).
>
> Tie the drain lead to the relay coil, and put a diode across the coil
> (reverse biased) to limit inductive kickback.
>
Comments
On an N-channel MOSFET which is similar to an NPN transistor:
COLLECTOR = DRAIN
BASE = GATE
EMITTER = SOURCE
Don <renegade.engineer@v...> wrote: Another semiconductor question: how
do the drain, source, and gate on a
MOSFET equate to the base, collector, and emitter on a standard transistor?
Don
>
> Tie the gate to the stamp pin, no resistor is required as the mosfet's
gate
> load is less than a microamp at dc and only a small capacitive load, if
you
> prefer you could use a resistor anything from 470 ohms through 1 meg will
> do. (I personally use a 10K if anything, because I accidentally ordered
ten
> thousand 10,000 ohm resistors).
>
> Tie the drain lead to the relay coil, and put a diode across the coil
> (reverse biased) to limit inductive kickback.
>
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[noparse][[/noparse]Non-text portions of this message have been removed]
They are not equal, they don't equate!
At the silicon level a MOSFET's source and drain can be interchanged
equally because they both sit in the same NWELL or PWELL and there
are no physical differences between them. In the real world sometimes
you cannot reverse Source and Drain because often there is a Diode
across them due to some manufacturing processes creating a PN junction or
by design, sometimes a diode is placed on purpose to help prevent silicon
latch-up.
NMOS:
P SSS GGG DDD P
PPPPPPPPPPPPPPP
PMOS:
P N SSS GGG DDD N P
P NNNNNNNNNNNNNNN P
PPPPPPPPPPPPPPPPPPP
Bipolar transistor's on the other hand can not exchange emitter and collector
because they sit in different wells with each transistor component creating
a pseudo-well if you will. i.e. the Emitter sits in the Base well while the
Emitter and Base both sit in the Collector Well. The Well in which the
Collector sits in determines the type of transistor NPN or PNP.
NPN:
P CCC BBB EEE BBB CCC P
P CCC BBBBBBBBBBB CCC P
P CCCCCCCCCCCCCCCCCCC P
PPPPPPPPPPPPPPPPPPPPPPP
PNP:
P N CCC BBB EEE BBB CCC N P
P N CCC BBBBBBBBBBB CCC N P
P N CCCCCCCCCCCCCCCCCCC N P
P NNNNNNNNNNNNNNNNNNNNNNN P
PPPPPPPPPPPPPPPPPPPPPPPPPPP
Key:
N - N+WELL
P - P+WELL (sub)
S - Source/Drain
D - Drain/Source
> Another semiconductor question: how do the drain, source, and gate on a
>MOSFET equate to the base, collector, and emitter on a standard transistor?
>Don
> >
> > Tie the gate to the stamp pin, no resistor is required as the mosfet's
>gate
> > load is less than a microamp at dc and only a small capacitive load, if
>you
> > prefer you could use a resistor anything from 470 ohms through 1 meg will
> > do. (I personally use a 10K if anything, because I accidentally ordered
>ten
> > thousand 10,000 ohm resistors).
> >
> > Tie the drain lead to the relay coil, and put a diode across the coil
> > (reverse biased) to limit inductive kickback.
> >
Beau Schwabe Mask Designer IV - ATL
National Semiconductor Enterprise Networking Business Unit
500 Pinnacle Court, Suite 525 Wired Communications Division
Mail Stop GA1 Norcross, GA 30071
Don
Original Message
From: "Randy Knutson" <ken_ryder@y...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, June 06, 2002 11:38 AM
Subject: Re: [noparse][[/noparse]basicstamps] Semiconductors (???????)
>
> Don:
> On an N-channel MOSFET which is similar to an NPN transistor:
> COLLECTOR = DRAIN
> BASE = GATE
> EMITTER = SOURCE
>
> Don <renegade.engineer@v...> wrote: Another semiconductor
question: how do the drain, source, and gate on a
> MOSFET equate to the base, collector, and emitter on a standard
transistor?
> Don
> >
> > Tie the gate to the stamp pin, no resistor is required as the mosfet's
> gate
> > load is less than a microamp at dc and only a small capacitive load, if
> you
> > prefer you could use a resistor anything from 470 ohms through 1 meg
will
> > do. (I personally use a 10K if anything, because I accidentally ordered
> ten
> > thousand 10,000 ohm resistors).
> >
> > Tie the drain lead to the relay coil, and put a diode across the coil
> > (reverse biased) to limit inductive kickback.
> >
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
> Do You Yahoo!?
> Sign-up for Video Highlights of 2002 FIFA World Cup
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>