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Faster than 2n7002

Started by Unknown April 15, 2015
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
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
Nice- worth having some on hand just for the low voltage drive. 5.3 ohms Rds(on) with 1.8V drive. Thanks!
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
Yes, very nice. Only $0.18 at Digi-Key. But what is that package, damn it's small! -- Thanks, - Win
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. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Wednesday, April 15, 2015 at 4:48:36 PM UTC-4, 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
> > That series gate resistor may trash the speed. The data sheet suggests > that it does.
I was thinking it's faster for nano-power one-cell stuff, where picofarads matter. I realize my subject line wasn't specific enough. I found the FET looking for a realllyyyy low-voltage part for low-voltage fun, but, after our thread on the 2n7002, I thought it was also nifty to see built-in ESD protection. I had a customer kill some BSS138s on a board's internal nodes last year, mishandling. ZAP! Who expects electro-static discharge there? But, the boards died, and a protected FET would not have failed.
> > 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.
Nice trick. Cheers, James Arthur
On Wednesday, April 15, 2015 at 4:33:28 PM UTC-4, Winfield Hill 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/mosfet/rum001l02.pdf > > Yes, very nice. Only $0.18 at Digi-Key. > But what is that package, damn it's small!
Yes, Rohm does that a lot. Fortunately, with SMD it's just a footprint. I like the idea of .8v logic, oscillators, (noisy) amplifiers, etc. Cheers, James Arthur
On Wed, 15 Apr 2015 14:40:26 -0700 (PDT), dagmargoodboat@yahoo.com
wrote:

>On Wednesday, April 15, 2015 at 4:48:36 PM UTC-4, 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 > >> >> That series gate resistor may trash the speed. The data sheet suggests >> that it does. > >I was thinking it's faster for nano-power one-cell stuff, where >picofarads matter. I realize my subject line wasn't specific enough.
"Fast" begins at 1 ns. "Really fast" at 100 ps.
> >I found the FET looking for a realllyyyy low-voltage part for low-voltage >fun, but, after our thread on the 2n7002, I thought it was also nifty to >see built-in ESD protection. > >I had a customer kill some BSS138s on a board's internal nodes last year, >mishandling. ZAP! Who expects electro-static discharge there? But, >the boards died, and a protected FET would not have failed.
Having grown up in New Orleans, and living in San Francisco, I tend to forget that some places have ESD.
> >> >> 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. > >Nice trick.
Most mosfets will switch a lot faster than their data sheets imply. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
On Wednesday, April 15, 2015 at 4:13:51 PM UTC-4, Spehro Pefhany 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 > > Nice- worth having some on hand just for the low voltage drive. 5.3 > ohms Rds(on) with 1.8V drive. > > Thanks!
Sure. Here's a beefier, 50V part, ESD-protected, Vth<=1.0V @ 1mA. http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/mosfet/rum002n05.pdf Capacitances are half of a 2n7002A's, and Rds(on) is a bit less too. (John-the-Ripper might like this one better.) About $0.06 by the reel. Rohm has all sorts of 1.0Vth MOSFETs, even 2.5A P-ch parts for under ten cents. Cheers, James Arthur
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
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.