Dual gate MOSFET.

I

ian field

Guest
Gone are the days when I used to service TV sets and could easily obtain the
occasional BF981 from a scrap tuner.

These days I obtain the occasional modern miniature tuners with very tiny
SMD MOSFETs with no markings, The Peak/Atlas component analyser will read it
as a MOSFET with the 3rd test lead connected to either gate in turn, but it
can't tell which way round the d & s pins are or which gate is which.

Anyone know of a way to determine these finer points?

TIA.
 
ian field schrieb:

Gone are the days when I used to service TV sets and could easily obtain the
occasional BF981 from a scrap tuner.

These days I obtain the occasional modern miniature tuners with very tiny
SMD MOSFETs with no markings, The Peak/Atlas component analyser will read it
as a MOSFET with the 3rd test lead connected to either gate in turn, but it
can't tell which way round the d & s pins are or which gate is which.

Anyone know of a way to determine these finer points?
Click to expand...
Perhaps you have a short look at the data sheet(s) of NXPs BF99x series.
They all share the same package and pinout and are pretty common.

.---.
G2 -| |- D
| |
G1 -| |= S (larger)
`---´

Tilmann

--
http://www.autometer.de - Elektronik nach Maß.
 
"Tilmann Reh" <tilmannreh@despammed.com> wrote in message
news:478c6108$0$25378$9b4e6d93@newsspool4.arcor-online.net...
ian field schrieb:

Gone are the days when I used to service TV sets and could easily obtain
the
occasional BF981 from a scrap tuner.

These days I obtain the occasional modern miniature tuners with very tiny
SMD MOSFETs with no markings, The Peak/Atlas component analyser will read
it
as a MOSFET with the 3rd test lead connected to either gate in turn, but
it
can't tell which way round the d & s pins are or which gate is which.

Anyone know of a way to determine these finer points?

Perhaps you have a short look at the data sheet(s) of NXPs BF99x series.
They all share the same package and pinout and are pretty common.

.---.
G2 -| |- D
| |
G1 -| |= S (larger)
`---´

Tilmann

--
http://www.autometer.de - Elektronik nach Maß.
Click to expand...
Thanks that might work - do the far-eastern manufacturers follow the same
pin layout?
 
ian field wrote:
"Tilmann Reh" <tilmannreh@despammed.com> wrote in message
news:478c6108$0$25378$9b4e6d93@newsspool4.arcor-online.net...
ian field schrieb:

Gone are the days when I used to service TV sets and could easily obtain
the
occasional BF981 from a scrap tuner.

These days I obtain the occasional modern miniature tuners with very tiny
SMD MOSFETs with no markings, The Peak/Atlas component analyser will read
it
as a MOSFET with the 3rd test lead connected to either gate in turn, but
it
can't tell which way round the d & s pins are or which gate is which.

Anyone know of a way to determine these finer points?
Perhaps you have a short look at the data sheet(s) of NXPs BF99x series.
They all share the same package and pinout and are pretty common.

.---.
G2 -| |- D
| |
G1 -| |= S (larger)
`---´

Tilmann

--
http://www.autometer.de - Elektronik nach Maß.

Thanks that might work - do the far-eastern manufacturers follow the same
pin layout?
Click to expand...
Nope, not always. It's all over the map, for example this one:

http://rocky.digikey.com/WebLib/NEC/Web%20Photos/New%20Photos/51-79A.jpg

--
Regards, Joerg

http://www.analogconsultants.com/
 
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