https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email MiniCircuits calls these both MMICs and Transistors, but they sure look like bare transistors. The 45 MHz lower frequency limit is strange. THey do have DC curves, which is refreshing in an RF part. Rds-on, seldom specified for an RF part, looks like about 5 ohms. I wish they had Spice models.
more phemts
Started by ●October 26, 2023
Reply by ●October 26, 20232023-10-26
john larkin <jl@650pot.com> wrote:> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email > > MiniCircuits calls these both MMICs and Transistors, but they sure > look like bare transistors. > > The 45 MHz lower frequency limit is strange. > > THey do have DC curves, which is refreshing in an RF part. > > Rds-on, seldom specified for an RF part, looks like about 5 ohms. > > I wish they had Spice models. >I do not find the DC curves in the datasheet. Can you give a hint? -- Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------
Reply by ●October 26, 20232023-10-26
Uwe Bonnes <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:> john larkin <jl@650pot.com> wrote: >> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >> >> MiniCircuits calls these both MMICs and Transistors, but they sure >> look like bare transistors. >> >> The 45 MHz lower frequency limit is strange. >> >> THey do have DC curves, which is refreshing in an RF part. >> >> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >> >> I wish they had Spice models. >> > > I do not find the DC curves in the datasheet. Can you give a hint?"DC curves" are tables in the "View Graphs" ... -- Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------
Reply by ●October 26, 20232023-10-26
On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:>john larkin <jl@650pot.com> wrote: >> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >> >> MiniCircuits calls these both MMICs and Transistors, but they sure >> look like bare transistors. >> >> The 45 MHz lower frequency limit is strange. >> >> THey do have DC curves, which is refreshing in an RF part. >> >> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >> >> I wish they had Spice models. >> > >I do not find the DC curves in the datasheet. Can you give a hint?Data sheet page 3. That suggets operation down to DC. The 45 MHz might be caused by coupling caps on the eval board or something. I want to use parts like these as switches. Some MMICs have internal bias circuits that indeed wreck the low frequency response.
Reply by ●October 26, 20232023-10-26
On 10/26/2023 23:13, john larkin wrote:> On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes > <bon@hertz.ikp.physik.tu-darmstadt.de> wrote: > >> john larkin <jl@650pot.com> wrote: >>> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >>> >>> MiniCircuits calls these both MMICs and Transistors, but they sure >>> look like bare transistors. >>> >>> The 45 MHz lower frequency limit is strange. >>> >>> THey do have DC curves, which is refreshing in an RF part. >>> >>> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >>> >>> I wish they had Spice models. >>> >> >> I do not find the DC curves in the datasheet. Can you give a hint? > > Data sheet page 3. That suggets operation down to DC. > > The 45 MHz might be caused by coupling caps on the eval board or > something. I want to use parts like these as switches. > > Some MMICs have internal bias circuits that indeed wreck the low > frequency response. >They do look interesting as switches indeed. Are they JFET-s? That gate-source +0.7V max and the max gate current suggest sort of that, although 0.7 looks too high. I have biased (during wrestling this or that, not in an end product IIRC) JFETS slightly above 0 G-S to get even less channel resistance but they must have brought that to a new level somehow.
Reply by ●October 26, 20232023-10-26
On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com> wrote:>On 10/26/2023 23:13, john larkin wrote: >> On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes >> <bon@hertz.ikp.physik.tu-darmstadt.de> wrote: >> >>> john larkin <jl@650pot.com> wrote: >>>> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >>>> >>>> MiniCircuits calls these both MMICs and Transistors, but they sure >>>> look like bare transistors. >>>> >>>> The 45 MHz lower frequency limit is strange. >>>> >>>> THey do have DC curves, which is refreshing in an RF part. >>>> >>>> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >>>> >>>> I wish they had Spice models. >>>> >>> >>> I do not find the DC curves in the datasheet. Can you give a hint? >> >> Data sheet page 3. That suggets operation down to DC. >> >> The 45 MHz might be caused by coupling caps on the eval board or >> something. I want to use parts like these as switches. >> >> Some MMICs have internal bias circuits that indeed wreck the low >> frequency response. >> > >They do look interesting as switches indeed. >Are they JFET-s? That gate-source +0.7V max and the max gate >current suggest sort of that, although 0.7 looks too high. >I have biased (during wrestling this or that, not in an end >product IIRC) JFETS slightly above 0 G-S to get even less >channel resistance but they must have brought that to a >new level somehow.These are phemts, which are enhancement mode parts that turn on at a few tenths of a volt. Capacitances are crazy low. We use them as switches, typically to discharge a timing ramp capacitor or some such. I have taken a lot of data on their SAV541 and SAV551 parts, which look very similar. I can post that if anyone is interested. The SAVs have wire bonds inside; maybe these don't. I did find remarkable effects if they are driven past suggested data sheet limits. They just keep enhancing! The Supertex depletion-mode mosfets enhance some too.
Reply by ●October 26, 20232023-10-26
On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com> wrote:>On 10/26/2023 23:13, john larkin wrote: >> On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes >> <bon@hertz.ikp.physik.tu-darmstadt.de> wrote: >> >>> john larkin <jl@650pot.com> wrote: >>>> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >>>> >>>> MiniCircuits calls these both MMICs and Transistors, but they sure >>>> look like bare transistors. >>>> >>>> The 45 MHz lower frequency limit is strange. >>>> >>>> THey do have DC curves, which is refreshing in an RF part. >>>> >>>> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >>>> >>>> I wish they had Spice models. >>>> >>> >>> I do not find the DC curves in the datasheet. Can you give a hint? >> >> Data sheet page 3. That suggets operation down to DC. >> >> The 45 MHz might be caused by coupling caps on the eval board or >> something. I want to use parts like these as switches. >> >> Some MMICs have internal bias circuits that indeed wreck the low >> frequency response. >> > >They do look interesting as switches indeed. >Are they JFET-s? That gate-source +0.7V max and the max gate >current suggest sort of that, although 0.7 looks too high. >I have biased (during wrestling this or that, not in an end >product IIRC) JFETS slightly above 0 G-S to get even less >channel resistance but they must have brought that to a >new level somehow.They are not JFETS. MiniCircuits has a good summary. .<https://blog.minicircuits.com/mmic-technologies-pseudomorphic-high-electron-mobility-transistor-phemt/> People have observed that pHEMTs seem to have relatively low flicker noise for a GHz amplifier. My guess is that this is because very clean materials and processes are needed to make a pHEMT. Joe Gwinn
Reply by ●October 27, 20232023-10-27
john larkin <jl@650pot.com> wrote:> On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com> > wrote: > >> On 10/26/2023 23:13, john larkin wrote: >>> On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes >>> <bon@hertz.ikp.physik.tu-darmstadt.de> wrote: >>> >>>> john larkin <jl@650pot.com> wrote: >>>>> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >>>>> >>>>> MiniCircuits calls these both MMICs and Transistors, but they sure >>>>> look like bare transistors. >>>>> >>>>> The 45 MHz lower frequency limit is strange. >>>>> >>>>> THey do have DC curves, which is refreshing in an RF part. >>>>> >>>>> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >>>>> >>>>> I wish they had Spice models. >>>>> >>>> >>>> I do not find the DC curves in the datasheet. Can you give a hint? >>> >>> Data sheet page 3. That suggets operation down to DC. >>> >>> The 45 MHz might be caused by coupling caps on the eval board or >>> something. I want to use parts like these as switches. >>> >>> Some MMICs have internal bias circuits that indeed wreck the low >>> frequency response. >>> >> >> They do look interesting as switches indeed. >> Are they JFET-s? That gate-source +0.7V max and the max gate >> current suggest sort of that, although 0.7 looks too high. >> I have biased (during wrestling this or that, not in an end >> product IIRC) JFETS slightly above 0 G-S to get even less >> channel resistance but they must have brought that to a >> new level somehow. > > These are phemts, which are enhancement mode parts that turn on at a > few tenths of a volt. Capacitances are crazy low. We use them as > switches, typically to discharge a timing ramp capacitor or some such. > > I have taken a lot of data on their SAV541 and SAV551 parts, which > look very similar. I can post that if anyone is interested. The SAVs > have wire bonds inside; maybe these don't. > > I did find remarkable effects if they are driven past suggested data > sheet limits. They just keep enhancing! > > The Supertex depletion-mode mosfets enhance some too. > >Any and all measurements welcome! Thanks Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by ●October 27, 20232023-10-27
On Fri, 27 Oct 2023 03:06:22 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>john larkin <jl@650pot.com> wrote: >> On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com> >> wrote: >> >>> On 10/26/2023 23:13, john larkin wrote: >>>> On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes >>>> <bon@hertz.ikp.physik.tu-darmstadt.de> wrote: >>>> >>>>> john larkin <jl@650pot.com> wrote: >>>>>> https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email >>>>>> >>>>>> MiniCircuits calls these both MMICs and Transistors, but they sure >>>>>> look like bare transistors. >>>>>> >>>>>> The 45 MHz lower frequency limit is strange. >>>>>> >>>>>> THey do have DC curves, which is refreshing in an RF part. >>>>>> >>>>>> Rds-on, seldom specified for an RF part, looks like about 5 ohms. >>>>>> >>>>>> I wish they had Spice models. >>>>>> >>>>> >>>>> I do not find the DC curves in the datasheet. Can you give a hint? >>>> >>>> Data sheet page 3. That suggets operation down to DC. >>>> >>>> The 45 MHz might be caused by coupling caps on the eval board or >>>> something. I want to use parts like these as switches. >>>> >>>> Some MMICs have internal bias circuits that indeed wreck the low >>>> frequency response. >>>> >>> >>> They do look interesting as switches indeed. >>> Are they JFET-s? That gate-source +0.7V max and the max gate >>> current suggest sort of that, although 0.7 looks too high. >>> I have biased (during wrestling this or that, not in an end >>> product IIRC) JFETS slightly above 0 G-S to get even less >>> channel resistance but they must have brought that to a >>> new level somehow. >> >> These are phemts, which are enhancement mode parts that turn on at a >> few tenths of a volt. Capacitances are crazy low. We use them as >> switches, typically to discharge a timing ramp capacitor or some such. >> >> I have taken a lot of data on their SAV541 and SAV551 parts, which >> look very similar. I can post that if anyone is interested. The SAVs >> have wire bonds inside; maybe these don't. >> >> I did find remarkable effects if they are driven past suggested data >> sheet limits. They just keep enhancing! >> >> The Supertex depletion-mode mosfets enhance some too. >> >> > >Any and all measurements welcome! > >Thanks > >Phil HobbsHere's some random measurements. https://www.dropbox.com/scl/fo/944svmozmwh4cfploqhyv/h?rlkey=gjueh508twp483vq20dlkeaq1&dl=0 In another case, I pulsed the gate positive at a low duty cycle, and it just kept conducting harder. I went to +1.2 volts. That is probably long-term bad news, but they sure switched hard. The models are based on your models, tweaked a bit per measurements. The xray shows the geometry and wire bonds. My Colpotts oscillator kept doing weird things, probably GHz oscillations, which was fixed with a *500 ohm* gate resisor.
Reply by ●October 27, 20232023-10-27
On Thu, 26 Oct 2023 10:19:50 -0700, john larkin <jl@650pot.com> wrote:>https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email > >MiniCircuits calls these both MMICs and Transistors, but they sure >look like bare transistors. > >The 45 MHz lower frequency limit is strange. > >THey do have DC curves, which is refreshing in an RF part. > >Rds-on, seldom specified for an RF part, looks like about 5 ohms. > >I wish they had Spice models.Package size and pinout is roughly equivalent to HP 'minipak' used for HMPP-3890/92/95. RL
