Forums

Faster than 2n7002

Started by Unknown April 15, 2015
In article <mgmhu702cir@drn.newsguy.com>,
 Winfield Hill <hill@rowland.harvard.edu> wrote:

> dagmargoodboat@yahoo.com wrote... > > > > Cool part. 20V enhancement N-ch MOSFET. > > Vgs.th(100uA) <= 1.0V > > capacitances ~1/5th of a 2n7002 at 1V. > > ESD protected. > > > >http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/mos > >fet/rum001l02.pdf > > Yes, very nice. Only $0.18 at Digi-Key. > But what is that package, damn it's small!
That's a fairly standard size - still within range of Press-n-Peel Blue and a cheap laser printer for hobbyists. After years of building bulky, hot, expensive, fragile boards from Radio Shack and Electronics Plus, I like the idea of fitting a 50W switching power supply onto a 1" square board. -- I will not see posts from astraweb, theremailer, dizum, or google because they host Usenet flooders.
On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin
<jlarkin@highlandtechnology.com> wrote in
<7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>:

>Having grown up in New Orleans, and living in San Francisco, I tend to >forget that some places have ESD.
Walk a mile in my shoes.... I draw 1 inch sparks in the supermarket, to the point that it hurts. Did not crash the cash register yet. I once designed the data network for a large supermarket chain, zeners everywhere.
On Thu, 16 Apr 2015 06:57:54 GMT, the renowned Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:

>On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin ><jlarkin@highlandtechnology.com> wrote in ><7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>: > >>Having grown up in New Orleans, and living in San Francisco, I tend to >>forget that some places have ESD. > >Walk a mile in my shoes....
>I draw 1 inch sparks in the supermarket, to the point that it hurts. >Did not crash the cash register yet.
The real reason for those ESD-safe wooden shoes?
>I once designed the data network for a large supermarket chain, >zeners everywhere.
Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
On a sunny day (Thu, 16 Apr 2015 08:25:59 -0400) it happened Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote in
<ehavia5p312mgc5l1k24mitck33k5pc1bc@4ax.com>:

>On Thu, 16 Apr 2015 06:57:54 GMT, the renowned Jan Panteltje ><pNaonStpealmtje@yahoo.com> wrote: > >>On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin >><jlarkin@highlandtechnology.com> wrote in >><7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>: >> >>>Having grown up in New Orleans, and living in San Francisco, I tend to >>>forget that some places have ESD. >> >>Walk a mile in my shoes.... > >>I draw 1 inch sparks in the supermarket, to the point that it hurts. >>Did not crash the cash register yet. > >The real reason for those ESD-safe wooden shoes?
I dunno, something the soles are made of..
On 4/16/2015 7:25 AM, Spehro Pefhany wrote:
> On Thu, 16 Apr 2015 06:57:54 GMT, the renowned Jan Panteltje > <pNaonStpealmtje@yahoo.com> wrote: > >> On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin >> <jlarkin@highlandtechnology.com> wrote in >> <7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>: >> >>> Having grown up in New Orleans, and living in San Francisco, I tend to >>> forget that some places have ESD. >> >> Walk a mile in my shoes.... > >> I draw 1 inch sparks in the supermarket, to the point that it hurts. >> Did not crash the cash register yet. > > The real reason for those ESD-safe wooden shoes?
He's Dutch?
>> I once designed the data network for a large supermarket chain, >> zeners everywhere. > > > Best regards, > Spehro Pefhany >
On Thu, 16 Apr 2015 00:18:46 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

>On Wed, 15 Apr 2015 15:07:48 -0700 (PDT), the renowned >dagmargoodboat@yahoo.com wrote: > >> >>Rohm has all sorts of 1.0Vth MOSFETs, even 2.5A P-ch parts for under ten cents. > >Nice to see some options that trade off higher Rds(on) for input >capacitance, but still have modern low Vgs(th) in the 1V range. > >Last time I needed one, all I could find readily was the little guys >that can switch amperes at low voltage but have high gate capacitance. > >--sp
Yea, that was the trend for MOSFETs anyways, but the newer devices have lower gate capacitances. Cheers
On Thu, 16 Apr 2015 08:25:59 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

>On Thu, 16 Apr 2015 06:57:54 GMT, the renowned Jan Panteltje ><pNaonStpealmtje@yahoo.com> wrote: > >>On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin >><jlarkin@highlandtechnology.com> wrote in >><7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>: >> >>>Having grown up in New Orleans, and living in San Francisco, I tend to >>>forget that some places have ESD. >> >>Walk a mile in my shoes.... > >>I draw 1 inch sparks in the supermarket, to the point that it hurts. >>Did not crash the cash register yet. > >The real reason for those ESD-safe wooden shoes? > >>I once designed the data network for a large supermarket chain, >>zeners everywhere. > > >Best regards, >Spehro Pefhany
I always thought that electronic assembly should be done by naked girls sitting in tubs of tepid water. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Wed, 15 Apr 2015 23:11:45 -0700, Robert Baer
<robertbaer@localnet.com> wrote:

>John Larkin wrote: >> On Wed, 15 Apr 2015 12:31:14 -0700 (PDT), dagmargoodboat@yahoo.com >> wrote: >> >>> Cool part. 20V enhancement N-ch MOSFET. >>> >>> Vgs.th(100uA)<= 1.0V >>> capacitances ~1/5th of a 2n7002 at 1V. >>> ESD protected. >>> >>> http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/mosfet/rum001l02.pdf >>> >>> Cheers, >>> James Arthur >> >> That series gate resistor may trash the speed. The data sheet suggests >> that it does. >> >> I've made a pulser that uses two 2N7002s in parallel to drive a 1:1 >> transmission line transformer. It will make a 50 volt pulse into 50 >> ohms with rise/fall times below 2 ns. You've just got to drive the >> gates hard. >> >> >> >> > Also, isn't the resistor in the wrong place? Like external gate pin, >resistor, zener? > That way there is less chance of frapping the protecton zener. >
Yes. But the resistor itself might get vaporized or punched through by an ESD pulse. So, why have the resistor at all? -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On 4/16/2015 1:31 PM, John Larkin wrote:
> On Thu, 16 Apr 2015 08:25:59 -0400, Spehro Pefhany > <speffSNIP@interlogDOTyou.knowwhat> wrote: > >> On Thu, 16 Apr 2015 06:57:54 GMT, the renowned Jan Panteltje >> <pNaonStpealmtje@yahoo.com> wrote: >> >>> On a sunny day (Wed, 15 Apr 2015 14:58:10 -0700) it happened John Larkin >>> <jlarkin@highlandtechnology.com> wrote in >>> <7gntial1e9g9kj8lar5e2lnvv2taflk7bs@4ax.com>: >>> >>>> Having grown up in New Orleans, and living in San Francisco, I tend to >>>> forget that some places have ESD. >>> >>> Walk a mile in my shoes.... >> >>> I draw 1 inch sparks in the supermarket, to the point that it hurts. >>> Did not crash the cash register yet. >> >> The real reason for those ESD-safe wooden shoes? >> >>> I once designed the data network for a large supermarket chain, >>> zeners everywhere. >> >> >> Best regards, >> Spehro Pefhany > > I always thought that electronic assembly should be done by naked > girls sitting in tubs of tepid water. > >
Nononononono. Girls in hot tubs are far more dangerous than mere lightning. Ask anyone, especially wives. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On Thu, 16 Apr 2015 00:18:46 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

>On Wed, 15 Apr 2015 15:07:48 -0700 (PDT), the renowned >dagmargoodboat@yahoo.com wrote: > >> >>Rohm has all sorts of 1.0Vth MOSFETs, even 2.5A P-ch parts for under ten cents. > >Nice to see some options that trade off higher Rds(on) for input >capacitance, but still have modern low Vgs(th) in the 1V range. > >Last time I needed one, all I could find readily was the little guys >that can switch amperes at low voltage but have high gate capacitance. > >--sp
The 2N7002 still looks good for a lot of uses. -- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers jlarkin att highlandtechnology dott com http://www.highlandtechnology.com