Post by thread:[EE] Somebody makes zero volt gate MOSFETs

On Wed, Aug 17, 2011 at 5:50 PM, YES NOPE9 <spam_OUTyesTakeThisOuTnope9.com> wrote: > So says Rzzzzzzzzzzzz > My question is ... Â Who makes these transistors ? Â Where can you buy them ? > Where is a TOO ...... theory of operation ????? > Best > 99guspuppet They're called depletion mode devices. A conduction channel exists at zero gate volts and is depleted by applying a negative gate voltage. Check any semiconductor reference for a theory of operation. -- Martin K.

On Wed, Aug 17, 2011 at 5:50 PM, YES NOPE9 <.....yesKILLspam@spam@nope9.com> wrote: > So says Rzzzzzzzzzzzz > My question is ... Who makes these transistors ? Where can you buy them ? > Where is a TOO ...... theory of operation ????? > Best > 99guspuppet I remembered there was a PIClist post about this ages ago, the link below is still active... {Quote hidden}> On 15 Jul 2005: > > > The Holy Grail of MOSFETS is now available - dual or quad devices > > which can be programmed (or are programmed at the factory) for a zero > > gate threshold voltage (to a precision of 2mV). > > > > Article claims that circuits running on a supply voltage of 20mV are > > now practicable (which adds a whole new meaning to running on a flat > > battery). > > > > www.planetanalog.com/showArticle.jhtml?articleID=164302768 > > -- Brent Brown, Electronic Design Solutions 16 English Street, St Andrews, Hamilton 3200, New Zealand Ph: +64 7 849 0069 Fax: +64 7 849 0071 Cell: +64 27 433 4069 eMail: brent.brownKILLspamclear.net.nz

> They're called depletion mode devices. A conduction channel exists at > zero gate volts and is depleted by applying a negative gate voltage. > Check any semiconductor reference for a theory of operation. Depletion mode devices are useful (and fun when one is not accustomed to them) but these are different again. Note that the amount of gate charge and thus Vth can be user programmed !!! ALD say: These quad/dual N-channel matched-pair MOSFETs are level-matched at the factory using a floating-gate charge controller ALD calls EPAD, for electrically programmable analog device. The floating gate is polysilicon embedded in the gate oxide. The charge level on this gate controls the sensitivity of the MOSFET switch, and can be set with the EPAD programming tool. With CMOS, EPAD programming can set thresholds from 0.01 V to - 0.01 V with an offset voltage of just 2 mV. Thus, the zero-threshold MOSFET can be classified as either an enhancement-mode device (when operated above the threshold voltage) or a depletion-mode device (when operated at or below threshold voltage). The quad and dual MOSFET arrays have part numbers ALD110800 and ALD110900. Their gate threshold voltage is 0.0 V 0.01 V at 1 microamp. Pricing starts at 91 cents each in quantities of 1,000 pieces. Datasheet: http://aldinc.com/pdf/ALD110800.pdf Dual $3.16/1 http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=1014-1030-ND I think I posted the original reference (in 2005). Russel