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Mixed-signal model of CD4093

Started by bitrex November 30, 2017
Is there a mixed-signal model of the CD4093 NAND Schmitt available that 
can be used in LTSpice? One that includes power supply connections and 
shows realistic supply currents, etc.

Or any of that fashion of CMOS family such as hex inverters that can 
also be used as negative-feedback analog amplifiers
"bitrex"  wrote in message news:z34UB.8492$T44.7111@fx20.iad... 
>Is there a mixed-signal model of the CD4093 NAND Schmitt available that >can be used in LTSpice? One that includes power supply connections and >shows realistic supply currents, etc.
There is such a model in VSM (Labcenter / Proteus). Robert
bitrex <bitrex@de.lete.earthlink.net> wrote:

> Is there a mixed-signal model of the CD4093 NAND Schmitt available that > can be used in LTSpice? One that includes power supply connections and > shows realistic supply currents, etc.
> Or any of that fashion of CMOS family such as hex inverters that can > also be used as negative-feedback analog amplifiers
If you have Helmut's 74HC devices installed, the 74HC132 is a dual NAND Schmitt device. I don't know about the supply current - CMOS devices are extremely low current drain in DC static condition. The current drain increases when driving a capacitive load as the frequency increases, but I don't know if that shows up in Helmut's 74HC devices. The 74HC14 is a Schmitt inverter. You may run into problems using a Schmitt device in negative-feedback analog amplifiers. A possible solution is a non-Schmitt device such as a 74HC04, but this may have too much gain since it is a triple stage device. The 74HCU04 may be better suited for analog work since it is a single stage device. In either case, the drain current increases dramatically when the device is used near the switching threshold since both sides of the totem pole output are on.
On 12/01/2017 09:20 AM, Steve Wilson wrote:
> bitrex <bitrex@de.lete.earthlink.net> wrote: > >> Is there a mixed-signal model of the CD4093 NAND Schmitt available that >> can be used in LTSpice? One that includes power supply connections and >> shows realistic supply currents, etc. > >> Or any of that fashion of CMOS family such as hex inverters that can >> also be used as negative-feedback analog amplifiers > > If you have Helmut's 74HC devices installed, the 74HC132 is a dual NAND > Schmitt device. I don't know about the supply current - CMOS devices are > extremely low current drain in DC static condition. The current drain > increases when driving a capacitive load as the frequency increases, but I > don't know if that shows up in Helmut's 74HC devices. > > The 74HC14 is a Schmitt inverter. You may run into problems using a Schmitt > device in negative-feedback analog amplifiers. > > A possible solution is a non-Schmitt device such as a 74HC04, but this may > have too much gain since it is a triple stage device. > > The 74HCU04 may be better suited for analog work since it is a single stage > device. In either case, the drain current increases dramatically when the > device is used near the switching threshold since both sides of the totem > pole output are on. > > >
Thanks, I was interested in playing around with the "micropower boost" circuit using a 4093 someone posted a while back: <https://www.dropbox.com/s/q0jiimbllgiuew0/micropowerBoost.pdf?dl=0> which "abuses" the power supply connection to generate the boost voltage; the CD4000_v.lib that's available for LTSpice seems to reflect variations in the supply unidirectionally; that is you can ride a sine wave on top of a Schmitt oscillator's VDD supply and see that in the output, but anything occurring with independent sources on the output node doesn't seem to be reflected to VDD.
On Fri, 1 Dec 2017 14:51:10 +0100, "Robert Lacoste"
<see-alciom-dot-com@none.com> wrote:

>"bitrex" wrote in message news:z34UB.8492$T44.7111@fx20.iad... >>Is there a mixed-signal model of the CD4093 NAND Schmitt available that >>can be used in LTSpice? One that includes power supply connections and >>shows realistic supply currents, etc. > >There is such a model in VSM (Labcenter / Proteus). >Robert
The CD.../74HC... models provided in both LTspice _and_ PSpice are _behavior_ and not suitable for any analog simulation. You _could_ roll you own CD4093 Spice model using either... CA3046_3086_3127_CD4007.zip or CD4007_SPICE_MODEL.pdf on the Device Models & Subcircuits Page of my website. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | It's what you learn, after you know it all, that counts.
I have a complete CD4001 model based on the RIT transistor models (some 
tweaking was necessary; this model is verified against the real IC):
https://www.seventransistorlabs.com/Images/CD4001_TR.ckt
You'd have to add the schmitt trigger input circuit (also change the core 
logic function to NOR).

If your circuit does not rely on the schmitt trigger action, or creates its 
own (like the traditional 3-gate RC oscillator does), this will work as-is.

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Contract Design
Website: https://www.seventransistorlabs.com/

"bitrex" <bitrex@de.lete.earthlink.net> wrote in message 
news:z34UB.8492$T44.7111@fx20.iad...
> Is there a mixed-signal model of the CD4093 NAND Schmitt available that > can be used in LTSpice? One that includes power supply connections and > shows realistic supply currents, etc. > > Or any of that fashion of CMOS family such as hex inverters that can also > be used as negative-feedback analog amplifiers
On 12/01/2017 07:21 PM, Tim Williams wrote:
> I have a complete CD4001 model based on the RIT transistor models (some > tweaking was necessary; this model is verified against the real IC): > https://www.seventransistorlabs.com/Images/CD4001_TR.ckt > You'd have to add the schmitt trigger input circuit (also change the > core logic function to NOR). > > If your circuit does not rely on the schmitt trigger action, or creates > its own (like the traditional 3-gate RC oscillator does), this will work > as-is. > > Tim >
Thanks, should be a good starting point if it turns out I'd like to roll my own